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  • Aircraft Design, Testing and Performance  (68)
  • 42.75  (26)
  • 1950-1954  (94)
  • 1
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.33 (1954) nr.6 p.41
    Publication Date: 2013-03-01
    Description: Unter diesem Titel, indessen mit dem Zusatz „unter Benutzung des Materials der Kollektion Eisner, Dahlem" — die Sammlung befindet sich z.Zt. im Rijksmuseum van Natuurlijke Historie, Leiden — haben mein Freund Felix Bryk und ich die Gruppen Parnassius mnemosyne L., P. stubbendorfi Ménétr., P. eversmanni Ménétr., P. nordmanni Ménétr., P. clarius Eversm., P. clodius Ménétr., P. Orleans Ch. Oberth., P. apollonius Eversm., P. honrathi Staud. und A. Bang-Haas, P. bremeri Bremer, P. phoebus F., P. actius Eversm., P. jacquemontii Boisd., P. epaphus Ch. Oberth., P. tianschanicus Ch. Oberth., P. nomion Hb. und einen Teil von P. apollo L. kritisch bearbeitet, bis die Entwicklung der politischen Verhältnisse in Deutschland die weitere Herausgabe der „Parnassiana" durch uns unmöglich machte und dadurch unsere Arbeit unterbrach. Wäre der Weltkrieg nicht ausgebrochen, hätten wir wahrscheinlich einen Weg gefunden, um das uns an's Herz gewachsene Werk schon längst fortzusetzen. Bryk weilt nun in Stockholm, mein Wohnsitz ist Den Haag, die enge Zusammenarbeit der Vergangenheit ist nicht möglich. Ich habe mich deshalb gefragt, ob ich es ohne die Unterstützung von Bryk's tiefem Wissen um die Parnassier und ohne seine kritische Kontrolle wagen kann, allein mit der Revision der Gattung fortzufahren. Ich habe aber das Gefühl, damit doch einen Beitrag zu der Kenntnis dieser interessanten Lepidopteren-Familie leisten zu können, und habe mich angemutigt durch meine Leidener Freunde entschlossen, dies zu tun. Herr Professor Boschma, dem ich dafür zu grossem Dank verpflichtet bin, hat mir angeboten, für die Veröffentlichung meiner Arbeiten in einer Form sorgen zu wollen, die es gestatten wird, diese separat zu sammeln und als Fortsetzung der früheren Veröffentlichung in „Parnassiana" zu ge-
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 2
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.32 (1954) nr.24 p.291
    Publication Date: 2013-03-01
    Description: In the taxonomy of Coccoidea or scale insects much confusion is due to an insufficient knowledge of the type species of several genera. Especially our knowledge of some of the older genera is very incomplete, as the descriptions of their type species are extremely short and superficial from the modern point of view. The type specimens, on which the original descriptions of the genera were based, are distributed over several museums in all parts of the world; in some cases type material is no longer in existence, and as far as available it is seldom lent to persons in foreign countries. In consequence of this we have often to rely on the original description, as the type material is not available for examination. Signoret (Essai sur les Cochenilles, 1868-1876) was one of the first to describe the microscopical details of the genera and species which he introduced. He boiled his specimens in a solution of caustic potash to make microscopical preparations of the chitinous parts and did not hesitate to prepare even unique specimens ("que nous n'avons pas hésité à sacrifier dans l'intérêt de la science, tout en conservant les préparations bonnes à consulter, pensant qu'elles seraient ainsi plus utiles qu'une masse informe attachée à un épingle et qui ne peut présenter aucun caractère que l'on puisse énumérer"). In many cases, however, his descriptions are not detailed enough for the needs of present taxonomy. As the number of described species has increased greatly since Signoret's time, it has become necessary to pay attention to several minute details which were formerly of no importance to separate the species then known. In consequence of the superficial descriptions by earlier authors the concepts of several genera are rather vague. Ferris has emphasized that in order
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 3
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.33 (1954) nr.7 p.49
    Publication Date: 2013-03-01
    Description: In seiner Behandlung der Gattung Archon Hb. im Tierreich „Lepidoptera pars I" kommt Bryk am Schluss seiner Betrachtungen zu der Feststellung, dass sich die geographischen „Formen" (subspecies?) in drei Gruppen zusammenfassen lassen. Unbestreitbar sind davon der „bellargus-Kreis" und der Rassenkreis, der die verschiedenen subspecies aus Pontus und Armenien beheimatet. Unklar ist die dritte Gruppe, zu der Bryk A. apollinus Herbst und subsp. thracica Buresch vereinigt. Die Diagnosen, die Bryk für die verschiedenen Rassen gibt, zwingen mich, da ich sein tiefes Wissen von allem und sein Feingefühl für alles, was mit Parnassxus zu tun hat, kenne, zu der Annahme, dass ihm ein zu beschränktes oder unzuverlässiges Material bei seiner Arbeit zu Verfügung gestanden hat. Ich weiss aus eigener Erfahrung, das gerade von Archon ungezählte Exemplare mit falschen Fundortetiquetten im Umlauf sind, oder solche, die den Vermerk e.l. missen. Das letztere ist insofern von Bedeutung, als mir eine grosse Anzahl e.l. Archon — teilweise aus eigener Zucht — vorliegen, die die Berechtigung der Aufstellung geographischer Rassen geradezu lügenzustrafen scheinen. Das Zudhtmaterial zeigt die ganze Variabilitätsbreite der Art und erinnert beispielsweise bei syrischer Herkunft kaum noch an das typische Aussehen von subsp. bellargus Staud. Zucht von Parnassiern ergibt fast stets Tiere, die vom Typus der betreffenden Rasse abweichen, aber sie doch nicht so vollständig verleugnen, wie es bei der grossen Serie Material, Herkunft Beyrouth, in meiner Sammlung der Fall ist. Was ist aber der typische apollinus? Bryk führt als Fundort für den Typus „Umgebung von Aleppo (Insel Kurlak)" auf, gibt aber als Verbreitungsgebiet gleichzeitig „Kleinasien, Mesopotamien" an. Der Begriff „Klein-
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 4
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.33 (1954) nr.8 p.55
    Publication Date: 2013-03-01
    Description: Viele Sammler rümpfen die Nase über die Benennung von Formen. Deren Festhaltung ist indessen wichtig, um einen Überblick über die Variabilitätsbreite einer Species zu geben ; ein weiterer Vorteil der dadurch erhaltenen Übersicht ist, dass er es dem Systematiker leichter macht, die für eine subspecies characteristischen Merkmale innerhalb der Variabilitätsmöglichkeit der species festzulegen. Aus dieser Anschauung heraus benenne ich die folgenden Formen: Luehdorfia puziloi Ersch. cf f. pallida (m.). Grundfarbe des cf weissgelb, wie sie sonst nur ? zeigen. Patria : Sutschanski-Rudnik, Ussuri, ι cf Typus. subsp. coreana Mats. f. fasciata (m.). ι cf mit im Hinterflügel einer continuierlichen Binde vom Wurzelfelde über Mittelzelle nach dem unteren Ende der Hinterrandschwärze. Patria: Umg. Seishin, N. Korea, ι cf Typus. subsp. inexpecta Shelj. f. rubrocatenaria (m.). Die roten Prachtflecken des Hinterflügels sind ungewöhnlich stark entwickelt zu einer breiten Binde, wie sie für subsp. chinensis Leech typisch ist, während bei inexpecta die roten Flecke normal gerade angedeutet sind. Patria: Kanoyama, Japan, ι cf ι ? Typen. Sericinus telamon Donov. f. cellopura (m.). Mittelzellfleck im Vorderflügel oberseits verschwunden, unterseits schwach als f. binaria Bryk erhalten, Endzell fleck stark reduciert. Patria : Mien-shan, Prov. Shansi, ι cf Typus, ι cf Paratypus, ι S Paratypus (subsp. mandschuricus Rosen). subsp. shantungensis M. Hering f. cellopurissima (m.).
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 5
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.33 (1954) nr.2 p.11
    Publication Date: 2013-03-01
    Description: During a short stay at Bangkok on December 3rd, 1953, Professor H. Boschma observed that enormous quantities of minute insects were attracted by lamplight in the hotel of the Royal Dutch Airlines (K.L.M.) "Plaswijk" at the airport Laksi. From the enormous accumulations of these insects around the lamps he collected a sample which he entrusted to me for examination. This sample proved to consist almost entirely of a new species of mayfly which is described in the present paper. Caenis demoulini nov. spec. Female imago. Head and thorax uniformly yellowish brown. Eyes purple-black, prominent. Antennae grey-brown ; median ocellus prominent, colour light brown with a darker edge. Abdomen pale yellowish brown, at the dorsal surface with light browngrey markings, except on the last three tergites. Ventral surface paler, especially the last three segments. Stigmata in or near a faint black or grey spot. Cerci and filum terminale silver-white, rather densely covered with stiff, long, silvery hairs, except at the base of these caudal filaments, where the colour passes into a very light brown, whilst here the hairs abruptly become much shorter, and are placed more densely. Anterior legs grey-brown, median and posterior legs pure white with a very faint yellowish spot at the end of the femora. Wings vitreous, veins light grey, except subcosta and radius, which are dark grey-brown. Area subcostalis very light ferruginous. Measurements: body Q 3.5 mm wing Ç 2.9-3.0 mm
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 6
    facet.materialart.
    Unknown
    In:  Zoologische Verhandelingen (0024-1652) vol.22 (1954) nr.1 p.1
    Publication Date: 2013-03-01
    Description: OLETHREUTINAE (Eucosmidae auct., Eucosminae auct.) Introduction The study of the South Asiatic representatives of the subfamily Olethreutinae of the Tortricidae is difficult on account of various reasons. Our basic knowledge of this group of insects originates from the knowledge of the Palaearctic fauna; unfortunately the taxonomy, and especially the nomenclature of the European Olethreutinae has for a long time been in a deplorable state of confusion and only recent pioneer work along modern lines, chiefly by Obraztsov, leads to some order. Unavoidably this confusion throws a shadow upon the study of the Olethreutinae from other regions than the Palaearctis. Since genital characters are of cardinal importance for the classification of the genera and species of the present group, it is clear that a fundamental revision is necessary, because nobody has ever bothered about these characters before, at least with regard to the South Asiatic fauna. When describing species from that region classic authors, as e.g., Snellen, usually chose a convenient generic name, familiar to the students of the Palaearctic fauna, to attribute them to ; Meyrick, as conveniently, merged many species in one of some four of his enormous genera. Many species of Olethreutinae are ornated with intricate markings that are very difficult to describe in a terse diagnose, as was the habit with those older authors; these descriptions are still more difficult to read! Other species are uniform to such an extent that their identification is impossible without the use of genital characters. Furthermore, Meyrick
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 7
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.32 (1954) nr.21 p.233
    Publication Date: 2013-03-01
    Description: In 1950 I received from Mr. D. Hille Ris Lambers a strange Pseudococcid from Java which had been collected by Mr. F. W. Rappard, a senior forestry officer, who regularly collects aphids for Mr. Hille Ris Lambers on his tours of duty. As this insect was a coccid, it was transmitted to me for examination. Its appearance is quite abnormal; the shape of its body reminds one almost of a large mite (fig. 4). The 6-segmented antennae have a dense vestiture of fine hairs, with exception of the 2 first segments which are very short. A tuft of 5 very long setae is present on the top of each of the anal lobes. The ungual digitules are extremely large and very flat. It was only after close study that the insect was recognized as a Pseudococcid. It has 2 pairs of ostioles in the usual position, a circulus on the ventral side of the second abdominal segment, and a few trilocular pores on both sides of the body. As I suspected an abnormal mode of living, I asked Mr. Hille Ris Lambers to write to Java for further particulars, and more material. To comply with this request Mr. Rappard has collected abundant material and communicated his field notes on these insects, which he calls "ant-riders" from their peculiar habit of climbing upon the black ants by which they are closely attended, as soon as these ants are disturbed, to have themselves transported in this way. The material at hand contains 3 different instars which seem to represent first and second stage larvae, and immature adult females. Of the latter stage only 3 specimens are available. Eggs or embryos were not observed in these specimens, but in one of them the oviduct and its exterior opening (one segment behind the posterior ostioles) is faintly visible in the chitinous
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 8
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.33 (1954) nr.11 p.69
    Publication Date: 2013-03-01
    Description: In the course of the year 1954 I received for identification a little Nematoceron belonging to the family Lycoriidae (Sciaridae). After a careful examination of the material and the literature I arrived at the conclusion that my specimens represented a hitherto undescribed species. It belongs to the genus Neosciara Pettey, 1918 (sensu Lengersdorf, 1930 and Frey, 1942). There is some confusion about the naming and delimitation of the genera in the subfamily Lycoriinae. The four most important opinions are : I. Lengersdorf (1930) : Genus Lycoria Meigen, 1800, syn. Saara Meigen, 1803, Gruppe I (no name, veins cu and m with bristles) and Gruppe II Neosciara Pettey, 1918 (cu and m bare). II. Séguy (1940) : Genus Lycoria Meigen, 1800 (cu and m with bristles) and S ciara Meigen, 1803 (veins cu and m bare). III. Frey (1942) : Genus Sciara Meigen, 1803, syn. Lycoria Meigen, 1800 (cu and m with bristles) and genus Neosciara Pettey, 1918 (cu and m without bristles). IV. Frey (1948): Genus Sciara Meigen, 1803 (cu and m with bristles) and genus Bradysia Winnertz, 1867, containing the subgenus Neosciara Pettey, 1918. The character concerning the bristles on the veins cu and m is very important for distinguishing these genera. When summarizing the above opinions we find that the species with bristles on cu and m have been named Lycoria Meigen, 1800 = Sciara Meigen, 1803 (Lengersdorf, 1930) ; Lycoria Meigen, 1800 (Séguy, 1940) ; Sciara Meigen, 1803 = Lycoria Meigen, 1800 (Frey, 1942, 1948). The species lacking setae on the veins cu and m have been named Neosciara Pettey, 1918 (Lengersdorf, 1930, Frey, 1942) ; Sciara
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 9
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.32 (1954) nr.22 p.259
    Publication Date: 2013-03-01
    Description: Apterous Aradidae were first brought to the attention of Hemipterists by N. C. E. Miller (Ann. Mag. Nat. Hist. [11] 1: 498-510, 1938). In fact it can be said that this paper with its excellent illustrations was the stimulus for the striking discoveries that have been made in this group in the past decade. The genus Chelonocoris Miller was proposed for a group of seven (actually 8 as is shown below) very large species from Malaya, Borneo, and (as it now appears) India. The present paper was prompted by the discovery in various European museums of several additional species which extend the known range of the genus to Java and Sumatra. In order to place these new species a key was prepared. The first key was based on Miller's types and was written while studying at the British Museum (Natural History) in 1949. A drastic revision of the key was necessitated when the species from Java and Sumatra were added. With the addition of the Sunda Island material certain inconsistencies became evident in the recorded distribution of the previously described species. I am indebted to N. C. E. Miller and W. E. China for their generous aid in straightening out these matters and for checking the revised key. It now appears that two species were included under the name Chelonocoris peregrinus Miller. The type is from Aring which is not in North Borneo but in India. The Malayan specimens represent a new species which is described below and dedicated to N. C. E. Miller in recognition of his pioneer work on apterous Aradidae. Another error which was detected by Miller and China is the drawing of the apex of the mesonotum in Chelonocoris malayensis (fig. 5c). Actually the mesonotum forms a continuous ridge in the female as in the male.
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 10
    Publication Date: 2019-05-25
    Description: An investigation was conducted on a 35 deg swept-wing fighter airplane to determine the effects of several blunt-trailing-edge modifications to the wing and tail on the high-speed stability and control characteristics and tracking performance. The results indicated significant improvement in the pitch-up characteristics for the blunt-aileron configuration at Mach numbers around 0.90. As a result of increased effectiveness of the blunt-trailing-edge aileron, the roll-off, customarily experienced with the unmodified airplane in wings-level flight between Mach numbers of about 0.9 and 1.0 was eliminated, The results also indicated that the increased effectiveness of the blunt aileron more than offset the large associated aileron hinge moment, resulting in significant improvement in the rolling performance at Mach numbers between 0.85 and 1.0. It appeared from these results that the tracking performance with the blunt-aileron configuration in the pitch-up and buffeting flight region at high Mach numbers was considerably improved over that of the unmodified airplane; however, the tracking errors of 8 to 15 mils were definitely unsatisfactory. A drag increment of about O.OOl5 due to the blunt ailerons was noted at Mach numbers to about 0.85. The drag increment was 0 at Mach numbers above 0.90.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-A54C31
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  • 11
    Publication Date: 2019-07-10
    Description: An investigation of the 1XP excitation of inclined single-rotation propellers has indicated a new concept for determining propeller shaft forces and moments of an inclined propeller. This report presents preliminary results, in particular to the counterrotating propeller.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-A54C30
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  • 12
    Publication Date: 2019-07-12
    Description: An investigation of a 1/14-scale dynamically similar model of a panto-base version of the Chase C-123 airplane was conducted to evaluate the hydrodynamic characteristics of the airplane. The resistance, longitudinal stability, and spray patterns during take-off and general behavior in calm- and rough-water landings were determined. Brief calm-water tests were made to compare the initial vertical impact accelerations of the model with and without hydro-skis. Take-off stability was satisfactory for calm-water operation. A ratio of gross load to maximum resistance of 3,6 was obtained. Heavy spray reached the propellers only during ski emergence. The landing behavior in calm water and in waves 3 feet by 150 feet (full scale) was satisfactory for a normal range of trim angles. Initial impacts in calmwater landings resulted in vertical accelerations of about 2 1/2 with the hydro-skis installed and about 4g with the hydro-skis removed,
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL54A28
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  • 13
    Publication Date: 2019-07-12
    Description: An investigation has been conducted to determine the static stability and control and damping in roll and yaw of a 0.13-scale model of the Convair XFY-1 airplane with propellers off from 0 deg to 90 deg angle of attack. The tests showed that a slightly unstable pitch-up tendency occurred simultaneously with a break in the normal-force curve in the angle-of-attack range from about 27 deg to 36 deg. The top vertical tail contributed positive values of static directional stability and effective dihedral up to an angle of attack of about 35 deg. The bottom tail contributed positive values of static directional stability but negative values of effective dihedral throughout the angle-of-attack range. Effectiveness of the control surfaces decreased to very low values at the high angles of attack, The model had positive damping in yaw and damping in roll about the body axes over the angle-of-attack range but the damping in yaw decreased to about zero at 90 deg angle of attack.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL54J04
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  • 14
    Publication Date: 2019-07-12
    Description: Additional results on the static longitudinal and lateral stability characteristics of a 0.05-scale model of the Convair F2Y-1 water-based fighter airplane were obtained in the Langley high-speed 7- by 10-foot tunnel over a Mach number range of 0.50 to 0.92. The maximum angle-of-attack range (obtained at the lower Mach numbers) was from -2 degrees to 25 degrees. The sideslip-angle range investigated was from -4 degrees to 12 degrees. The investigation included effects of various arrangements of wing fences, leading-edge chord-extensions, and leading-edge notches. Various fuselage fences, spoilers, and a dive brake also were investigated. From overall considerations of lift, drag, and pitching moments, it appears that there were two modifications somewhat superior to any of the others investigated: One was a configuration that employed a full-chord fence and a partial-chord fence located at 0.63 semispan and 0.55 semispan, respectively. The second was a leading-edge chord-extension that extended from 0.68 semispan to 0.85 semispan in combination with a leading-edge notch located at 0.68 semispan. With plus or minus 10 degrees aileron, the estimated wing-tip helix angle was reduced from 0.125 at a Mach number of 0.50 to 0.088 at a Mach number of 0.92, with corresponding rates of roll of 4.0 and 5.2 radians per second. The upper aft fuselage dive brake, when deflected 30 degrees and 60 degrees, reduced the rudder effectiveness about 10 to 20 percent and about 35 to 50 percent, respectively.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL54H05
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  • 15
    Publication Date: 2019-07-12
    Description: An investigation was conducted in the Langley 19-foot pressure tunnel on a 0.3-scale model of the Republic RF-84F airplane to determine modifications which would eliminate the pitch-up that occurred near maximum lift during flight tests of the airplane. The effects of high-lift and stall-control devices, horizontal tail locations, external stores, and various inlets on the longitudinal characteristics of the model were investigated. For the most part, these tests were conducted at a Reynolds number of 9.0 x 10(exp 6) and a Mach number of 0.19. The results indicated that from the standpoint of stability the inlets should possess blunted side bodies. The horizontal tail located at either the highest or lowest position investigated improved the stability of the model. Three configurations were found for the model equipped with the production tail which eliminated the pitch-up through the lift range up to the maximum lift and provided a stable static margin which did not vary more than 15% of the mean aerodynamic chord through the lift range up to 85% of maximum lift. The three configurations are as follows: the production wing-fuselage-tail combination with an inlet similar to the production inlet but smaller in plan form in conjunction with either (1) a wing fence located at 65% of the win semispan or (2) an 11.7% chord leading-edge extension extending from 65.8 to 95.8% of the wing semispan and (3) the production wing-fuselage-tail combination with the production inlet and an 11.7% chord leading-edge extension extending from 70.8 to 95.8% of the wing semispan.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL54B17
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  • 16
    Publication Date: 2019-07-12
    Description: Data were obtained in an altitude test chamber for a range of altitudes from 20,000 to 58,000 feet at a flight Mach number of 0.9, and for several flight Mach numbers at an altitude of 45,000 feet. Data approximating sea-level operation are also included. Engine component performance data are presented in addition to windmilling, exhaust-nozzle, and ejector performance.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SE54H06
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  • 17
    Publication Date: 2019-07-12
    Description: Altitude performance characteristics of the J65-B3 turbojet engine and its components were obtained at engine-inlet conditions corresponding to Reynolds number indices from 0.2 to 0.8 over a range of corrected engine speeds from 70 to 110 percent of rated speed. Engine operational limits up to an altitude of 75,000 feet together with ignition and windmilling characteristics were also obtained. The engine and component data are presented both in graphical and in tabulated form. The operational characteristics are presented in graphical form.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SE54H18
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  • 18
    Publication Date: 2019-07-12
    Description: An investigation was made of the take-off characteristics of a 1/10-scale dynamic model of the Convair XF2Y-1 airplane. This airplane is a water-based, jet-propelled, delta-wing fighter incorporating a hydro-ski landing gear. Tests were made with the original configuration, with the beaching wheels removed, and with the wheels installed and fairings added in front of the wheels. Each configuration was tested at weight and balance conditions simulating 17,000 pounds gross weight with the moment due t o 7,600 pounds of thrust, 17,300 pounds gross weight with a 9,500-pound thrust condition, and 23,000 pounds gross weight with a 9,300-pound thrust condition. Constant-speed runs were made at various elevon settings and vertical ski-strut positions; and trim, rise, and resistance were measured. Accelerated runs were made with controlled elevons and scale shock struts which could be extended as desired, and the longitudinal stability and spray characteristics were observed and photographed.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL54G08a
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  • 19
    Publication Date: 2019-07-12
    Description: Missions for which a rocket interceptor is suited and the effect of rocket-engine performance on interceptor performance are discussed. Flight missions for interceptors having rocket and turbojet engines are compared, and circumstances under which a combination of rocket and turbojet may be advantageous are discussed.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-E54D15
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  • 20
    Publication Date: 2019-07-12
    Description: Free-flight tests in the transonic speed range utilizing rocketpropelled models have been made on three pairs of 0.11-scale North American F-100 airplane wings having an aspect ratio of 3.47, a taper ratio of 0.308, 45 degree sweepback at the quarter-chord line, and thickness ratios of 31 and 5 percent to investigate the possibility of flutte r. Data from tests of two other rocket-propelled models which accidentally fluttered during a drag investigation of the North American F-100 airplane are also presented. The first set of wings (5 percent thick) was tested on a model which was disturbed in pitch by a moving tail and reached a maximum Mach number of 0.85. The wings encountered mild oscillations near the first - bending frequency at high lift coefficients. The second set of wings 9 percent thick was tested up to a maximum Mach number of 0.95 at (2) angles of attack provided by small rocket motors installed in the nose of the model. No oscillations resembling flutter were encountered during the coasting flight between separation from the booster and sustainer firing (Mach numbers from 0.86 to 0.82) or during the sustainer firing at accelerations of about 8g up to the maximum Mach number of the test (0.95). The third set of wings was similar to the first set and was tested up to a maximum Mach number of 1.24. A mild flutter at frequencies near the first-bending frequency of the wings was encountered between a Mach number of 1.15 and a Mach number of 1.06 during both accelerating and coasting flight. The two drag models, which were 0.ll-scale models of the North American F-100 airplane configuration, reached a maximum Mach number of 1.77. The wings of these models had bending and torsional frequencies which were 40 and 89 percent, respectively, of the calculated scaled frequencies of the full-scale 7-percent-thick wing. Both models experienced flutter of the same type as that experienced-by the third set of wings.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL54G29
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  • 21
    Publication Date: 2019-07-11
    Description: An investigation was conducted in the Langley 20-foot free-spinning tunnel on a 1/23-scale model of the McDonnell F3H-1N airplane. The effects of control settings and movements upon the erect and inverted spin and recovery characteristics of the model were determined for the clean condition. Spin-recovery parachute tests were also performed. The results indicated that erect spins obtained on the airplane for the take-off or combat loadings should be satisfactorily terminated if full rudder reversal is accompanied by moving the ailerons to full with the spin (stick full right in a right spin). The spins obtained should be oscillatory in pitch, roll, and yaw. Recoveries from inverted spins should be satisfactory by full reversal of the rudder. A 16.7-foot- diameter tail parachute with a towline length of 30 feet and a drag coefficient of 0.734 should be adequate for emergency recovery from demonstration spins.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL55A10a
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  • 22
    Publication Date: 2019-08-17
    Description: Measurement of average skin-friction coefficients have been made on six rocket-powered free-flight models by using the boundary-layer rake technique. The model configuration was the NACA RM-10, a 12.2-fineness-ratio parabolic body of revolution with a flat base. Measurements were made over a Mach number range from 1 to 3.7, a Reynolds number range 40 x 10(exp 6) to 170 x 10(exp 6) based on length to the measurement station, and with aerodynamic heating conditions varying from strong skin heating to strong skin cooling. The measurements show the same trends over the test ranges as Van Driest's theory for turbulent boundary layer on a flat plate. The measured values are approximately 7 percent higher than the values of the flat-plate theory. A comparison which takes into account the differences in Reynolds number is made between the present results and skin-friction measurements obtained on NACA RM-10 scale models in the Langley 4- by 4-foot supersonic pressure tunnel, the Lewis 8- by 6-foot supersonic tunnel, and the Langley 9-inch supersonic tunnel. Good agreement is shown at all but the lowest tunnel Reynolds number conditions. A simple empirical equation is developed which represents the measurements over the range of the tests.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L54G14
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  • 23
    Publication Date: 2019-08-14
    Description: The lift, pitching-moment, and drag characteristics of a missile configuration having a body of fineness ratio 9.33 and a cruciform triangular wing and tail of aspect ratio 4 were measured at a Mach number of 1.99 and a Reynolds number of 6.0 million, based on the body length. The tests were performed through an angle-of-attack range of -5 deg to 28 deg to investigate the effects on the aerodynamic characteristics of roll angle, wing-tail interdigitation, wing deflection, and interference among the components (body, wing, and tail). Theoretical lift and moment characteristics of the configuration and its components were calculated by the use of existing theoretical methods which have been modified for application to high angles of attack, and these characteristics are compared with experiment. The lift and drag characteristics of all combinations of the body, wing, and tail were independent of roll angle throughout the angle-of-attack range. The pitching-moment characteristics of the body-wing and body-wing- tail combinations, however, were influenced significantly by the roll angle at large angles of attack (greater than 10 deg). A roll from 0 deg (one pair of wing panels horizontal) to 45 deg caused a forward shift in the center of pressure which was of the same magnitude for both of these combinations, indicating that this shift originated from body-wing interference effects. A favorable lift - interference effect (lift of the combination greater than the sum of the lifts of the components) and a rearward shift in the center of pressure from a position corresponding to that for the components occurred at small angles of attack when the body was combined with either the exposed wing or tail surfaces. These lift and center-of-pressure interference effects were gradually reduced to zero as the angle of attack was increased to large values. The effect of wing-tail interference, which influenced primarily the pitching-moment characteristics, is dependent on the distance between the wing trailing vortex wake and the tail surfaces and thus was a function of angle of attack, angle of roll, and wing- tail interdigitation. Although the configuration at zero roll with the wing and tail in line exhibited the least center-of-pressure travel, the configuration with the wing and tail interdigitated had the least change in wing- tail interference over the angle - of-attack range. The lift effectiveness of the variable-incidence wing was reduced by more than 70 percent as a result of an increase in the combined angle of attack and wing incidence from 0 deg to 40 deg center dot The wing- tail interference (effective downwash at the tail) due to wing deflection was nearly zero as a result of a region of negative vorticity shed from the inboard portion of the wing. The lift characteristics of the configuration and its components were satisfactorily predicted by the calculated results, but the pitching moments at large angles of attack were not because of the influence of factors for which no adequate theory is available, such as the variation of the cross flow drag coefficient along the body and the effect of the wing downwash field on the after body loading.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-A54H27
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  • 24
    Publication Date: 2014-07-15
    Description: A method has been proposed for predicting the effect of a rapid blade-pitch increase on the thrust and induced-velocity response of a helicopter rotor. General equations have been derived for the ensuing motion of the helicopter. These equations yield time histories of thrust, induced velocity, and helicopter vertical velocity for given rates of blade-pitch-angle changes and given rotor-angular-velocity time histories. The results of the method have been compared with experimental results obtained with a rotor mounted on the Langley helicopter test tower. The calculated and experimental results are in good agreement, although, in general, the calculated thrust-coefficient overshoots are about 10 percent greater than those obtained experimentally.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-TN-3044
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  • 25
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.32 (1953) nr.9 p.87
    Publication Date: 2013-03-01
    Description: I have to thank Dr. H. C. Blöte of the Leiden Museum of Natural History for his kindness to entrust me with a number of Carabidae from Indonesia for identification. A few species appear to be new to science; the descriptions follow below. One genus, Horniulus Jedl., is new to the whole of the Malay Archipelago, and another, Bembidion Latr., is new to Sumatra. Of the latter genus there are already a couple of species known from Java. I am much obliged to Mr. E. B. Britton of the British Museum, who carefully compared a few species with specimens in the collections of the British Museum and in Andrewes' collections. The type specimens are in the Leiden Museum. Oxygnathopsis gen. nov. (fig. 1 f) (Andrewes (1938, p. 196) described Oxygnathus javanus upon a single specimen from Java. With regard to the proper genus Andrewes was not absolutely sure because of a number of important differences, but before introducing a new genus he preferred to wait till more material was available. In the sending of the Leiden Museum I found a second specimen, which shows the same characteristics as the specimen described by Andrewes, so that in my opinion a new genus is desirable. The two genera are to be distinguished as follows: 1 (2) Head with the clypeus bisetose, two setae on each side over the eyes, facial carinae and sulci present; prothorax with two lateral setae on each side. Range: Assam and Burma.........Oxygnathus Dej. 2 (1) Clypeus without setae, one supra-orbital seta, the front seta is wanting, no facial Fig. 1. a, Coptodera flavipes sp. n., left elytron; b, Horniulus quadrimaculatus sp. n.,
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 26
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.32 (1953) nr.3 p.31
    Publication Date: 2013-03-01
    Description: Eine Bestimmungssendung des Deutschen Entomologischen Institutes veranlasste mich, die Systematik der asiatischen Coenochilus zu studieren. Die Museen Leiden, Berlin und München und die Herren Frey, Haberäcker, Klapperich und van Nidek stellten mir ihr Material zur Verfügung; Herr Reichert des Museums Dresden und Herr Ruter des Museums Paris gaben bereitwillig Auskunft über Typen ihrer Museen. Ihnen alien sowie den Herren Prof. Dr. Sachtleben, Prof. Dr. Delkeskamp, Dr. C. de Jong, Dr. H. C. Blöte, Dr. Forster, H. Freude, P. Müller und St. von Breuning danke ich bestens für ihre Hilfe. Als Ergebnis meiner Studien veröffentliche ich hier die Beschreibung zweier neuer Arten und des ♂ von C. leopoldi Bourg. sowie eine aus der Arrow'schen Tabelle in der Fauna of British India weiterentwickelte Bestimmungstabelle aller asiatischen Arten. 1. Der Katalog von Junk-Schenkling Pars 72 aus 1921 ist auf Seite 366 f. durch folgende Arten zu ergänzen: assmuthi Wasmann, Wiener Ent. Zeit., vol. 37, 1918, S. 19. bifoveolatus Fairmaire, Ann. Soc. Ent. Fr., 1888, S. 344. leopoldi Bourgoin, Mem. Mus. Roy. H.N. Belg., 1933, Voyage Leopold, vol. IV fasc. 9, Col. II, S. 31. leveillei Nonfried, Berl. Ent. Zeit., 1891, S. 372, der nach Arrow kein Pilinurgus ist. obesus Wasmann, Wiener Ent. Zeit., vol. 37, 1918, S. 21. obscurus Westwood, Tijdsch. v. Ent., vol. 26, 1883, S. 62-65. platycerus Gerstäcker, von S. 368 des Kat. (1883). sumatranus Westwood, Tijdsch. v. Ent., vol. 26, 1883, S. 62-65. uncinatipes Moser, D. Ent. Zeit., 1915, S. 596.
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 27
    Publication Date: 2013-03-01
    Description: Contents ι. Introduction..............I 2. Systematics (a, The correct name of the genus p. 4; b, Diagnostic characters of the species and subspecies p. 6; c, Abbreviations p. 9; d, Key to the species and subspecies p. 10; e, Survey of the species and subspecies p. 11; f, Disregarded specimens p. 30; g, Wilcoxon tests for the difference between certain measurements in allied subspecies p. 31; h, Early stages p. 36; i, The species concept in Nyctalemon p. 37).......... 3. Biology............... 38 4. Distribution.............. 43 5. Evolution............... 46 6. Bibliography.............. 52 1. INTRODUCTION In November 1949 the late Professor Dr. L. J. Toxopeus of Bandung, Java, sent me a specimen of Nyctalemon for identification, but neither with the help of our collection, nor with the current literature did I succeed in ascertaining the correct name of this insect. On the contrary it appeared that, though the described forms of this genus clearly were of different value, viz., partly good species, partly geographical subspecies representing these species in restricted areas, no satisfactory division of the genus into species and subspecies had been given. Thus, Seitz' classification of the known forms into four species of which three are polytypic proved to make no sense. Therefore I resolved to study the genus more closely. In the ensuing correspondence Toxopeus gave me the benefit of his experience by providing references to relevant literature and quotations from
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 28
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.32 (1953) nr.18 p.203
    Publication Date: 2013-03-01
    Description: COPROMORPHIDAE Meyrick, 1905, Journ. Bombay Nat. Hist. Soc, vol. 16, p. 606. This small family represents a natural group with clearly marked characters, and is easy of descrimination. It inhabits tropical regions of Asia and extends through the Papuan region over the whole Pacific. The last mentioned region might be the country of origin of this group, as genera with peculiar and possibly archaic characters have been recorded from the Pacific Islands; some of those species are distinguished by an exceptionally large size. One of the interesting points with regard to the family is its possible place in the system. The long-ciliate or pectinate antennae, the neuration, and the complicated genital apparatus of the male seem to indicate an affinity with the Tineoidea. The general facies, however, is divergent to some extent, while the presence of a cubital pecten on the hind wings fundamentally discriminates this family from all the Tineoidea sensu stricto. When describing the family, Meyrick suggested that the cubital pecten might point towards an affinity with the Tortricoidea ; this relation, however, is not supported by any other characters. He further surmised that the Copromorphidae would be nearest allied to the Xyloryctidae ; in my opinion this surmise is devoid of any ground. Later Meyrick tried to combine with the Copromorphidae two other groups of "Tineina" that also are in possession of a cubital pecten, viz., the family Orneodidae, and the genus Hypertropha Meyr. The relation of the former with the Copromorphidae, however, is problematic, and deserves further proofs, while Hypertropha has in my opinion nothing in common with the family concerned, except for the
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 29
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.32 (1953) nr.5 p.43
    Publication Date: 2013-03-01
    Description: Some time ago I was asked to identify a fossil coleopteron which had been found in the drill cuttings of an oil well in the Southern part of Sumatra. As the fossil is only a few millimetres long it may be mentioned as an amazing fact that so small an object has been found during rather rough work like oil drilling. The details of the locality as given by Mr. A. Wright Jr. of the N.V. Standard-Vacuum Petroleum Maatschappij are as follows: "The well is one of our Kaja wells, a wildcat well located 3.3 kilometres N. 300 E. from the northeast edge of the Djirah oilfield. The drill cutting was obtained from a depth of 1930 feet subsea. Although, in drill cuttings, there is a certain measure of uncertainty as to the exact level of derivation, we have sufficient evidence to be sure that the fossil actually derives from this depth. The age is Tertiary-e; it occurs below beds of Baturadja stage age, but 200 feet above a lepidocyclina-bearing horizon. The fossil occurs in a shale interval of a formation which is generally non-fossiliferous; conditions were presumably marine, but either oligotrophe or toxic; the water at the time of deposition was shallow." The fossil is pyritized, dark bronze-greyish in colour. It is nearly free from substrate, though in some crevices a light grey, rather soft, somewhat fattish substance is found which can be taken away rather easily. The fossil was sent to the Rijksmuseum van Natuurlijke Historie at Leiden, mounted in a small box on a slide, pasted to the bottom with tragacanth. During the studies it was left in the small box, and kept in an exsiccator to preserve the fossil against deterioration by atmospheric influence.
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 30
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.32 (1953) nr.6 p.49
    Publication Date: 2013-03-01
    Description: I. Attacus dohertyi dammermani nov. subspec. (Plate II) Large, apex of fore wing moderately produced, general coloration of wings, head, notum including patagia, and abdomen rather light reddish brown, several intersegmental folds between the abdominal tergites blackish. In both wings the terminal area somewhat lighter, more yellowish brown, in apex of fore wing grading into yellowish. Hind wing with the apical area markedly reddish. In fore wing the dark apical spot and red dash weak, submarginal line practically wanting, in hind wing a somewhat undulating submarginal dark line well developed. Postmedian band in both wings strongly serrate, but not bent inwards. Antemedian band in both wings less distinct, not serrate, in fore wing angled on base of v2, in hind wing curved inwards. The vitreous patches in both wings very large, guttiform by having the base curved outwards, the basal angles rounded, and the top elongated and pointed towards the postmedian band. In both wings with two additional vitreous patches which are in fore wing slightly larger than in hind wing. In hind wing the lower patch communicates with the interior black border of the postmedian band. All these spots bordered by a black margin. The interior orange yellow border, so obvious in many dohertyi specimens, is wanting or indicated by some inconspicuous traces only. Underside corresponding with upperside, the outer half very light, as in atlas, but the subterminal markings in both wings practically wanting or obsolete. Lateral markings of abdomen much less developed than in atlas. I ♀, 25 cm, holotype, W. Sumba, IV. 1925, labelled Dammerman, Sumba Exp., in Museum Leiden. 2. THE SPECIES OF THE GENUS Attacus L. IN THE FAR EAST.
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 31
    Publication Date: 2019-07-11
    Description: A free-flight 0.12-scale rocket-boosted model of the North American MX-770 (X-10) missile has been tested in flight by the Pilotless Aircraft Research Division of the Langley Aeronautical Laboratory. Drag, longitudinal stability, and duct performance data were obtained at Mach numbers from 0.8 to 1.7 covering a Reynolds number range of about 9 x 10(exp 6) to 24 x 10(exp 6) based on wing mean aerodynamic chord. The lift-curve slope, static stability, and damping-in-pitch derivatives showed similar variations with Mach number, the parameters increasing from subsonic values in the transonic region and decreasing in the supersonic region. The variations were for the most part fairly smooth. The aerodynamic center of the configuration shifted rearward in the transonic region and moved forward gradually in the supersonic region. The pitching effectiveness of the canard control surfaces was maintained throughout the flight speed range, the supersonic values being somewhat greater than the subsonic. Trim values of angle of attack and lift coefficient changed abruptly in the transonic region, the change being associated with variations in the out-of-trim pitching moment, control effectiveness, and aerodynamic-center travel in this speed range. Duct total-pressure recovery decreased with increase in free-stream Mach number and the values were somewhat less than normal-shock recovery. Minimum drag data indicated a supersonic drag coefficient about twice the subsonic drag coefficient and a drag-rise Mach number of approximately 0.90. Base drag was small subsonically but was about 25 percent of the minimum drag of the configuration supersonically.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL53D10A
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  • 32
    Publication Date: 2019-07-11
    Description: An investigation was made to determine the static longitudinal and lateral stability and control characteristics of a l/6-scale model of the revised Republic XF-84H airplane with and without the propeller operating. The model had a 40deg swept wing of aspect ratio 3.45 and was equipped with a thin, three-blade supersonic-type propeller. Modifications incorporated in the revised model included a raised horizontal tail, increased rudder size, wing fences at 65 percent semispan, and a modified wing leading edge outboard of the fences. The test results for flap-retracted and flap-deflected conditions indicated that the revised configuration should be satisfactory for most normal flight conditions provided the angle of attack does not exceed the angle for pitch-up. An abrupt pitch-up tendency of the model was evident for the zero thrust condition above approximately 15' angle of attack. Although the effects of power were destabilizing, power-on longitudinal stability was satisfactory through the angle-of-attack range for which the model was stable with zero thrust. Above the angle of attack for pitch-up, an uncontrollable left roll-off tendency would be expected with power on and slats retracted. Projection of wing slats or use of leading-edge chord-extensions with only the left extension drooped were found beneficial in controlling the roll-off tendency with power on; however the most effective means found was projection of only the left slat.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL53I24
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  • 33
    Publication Date: 2019-06-28
    Description: Pressure-distribution measurements have been made on the fus elage of the Bell X- 1 research airplane. Data are presented for angles of attack from 2 deg. to 8 deg. during pull-ups at Mach numbers of about 0.78, 0.85, 0.88, and 1.02. The results of the investigation indicated that a large portion of the load carried by the fuselage was in the vicinity of the wing and may be attributed to wing-to-fuselage carryover. The presence of the wing from the 41 to 60 percent fuselage stations influenced the fuselage pressures from about 30 to 65 percent fuselage length at Mach numbers of approximat ely 0.78, 0.85, and 0.88, and from about 35 to 80 percent fuselage length at a Mach number of approximately 1.02. The fuselage contributed about 20 percent of the total airplane normal-force coefficient. The center of pressure of the fuselage load throughout the tests was located from 41 to 51 percent fuselage length, which corresponds to the forward half of the wing root-chord location.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L53I15
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  • 34
    Publication Date: 2019-07-12
    Description: An investigation has been made at high subsonic speeds of the aerodynamic'characteristics in pitch and sideslip of a l/l4-scale model of the Grumman XF10F airplane with a wing sweepback angle of 42.5. The longitudinal stability characteristics (with the horizontal tail fixed) indicate a pitch-up near the stall; however, this was somewhat alleviated by the addition of fins to the side of the fuselage below the horizontal tail. The original model configuration became directionally unstable for small sideslip angles at Mach numbers above 0.8; however, the instability was eliminated by several different modifications.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL53G20
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  • 35
    Publication Date: 2019-07-12
    Description: A limited investigation of a 1/24-scale dynamically similar model of the Navy Bureau of Aeronautics DR-77 design was conducted in Langley tank no. 2 to determine the calm-water take-off and the rough-water landing characteristics of the design with particular regard to the take-off resistance and the landing accelerations. During the take-off tests, resistance, trim, and rise were measured and photographs were taken to study spray. During the landing tests, motion-picture records and normal-acceleration records were obtained. A ratio of gross load to maximum resistance of 3.2 was obtained with a 30 deg. dead-rise hydro-ski installation. The maximum normal accelerations obtained with a 30 deg. dead-rise hydro-ski installation were of the order of 8g to log in waves 8 feet high (full scale). A yawing instability that occurred just prior to hydro-ski emergence was improved by adding an afterbody extension, but adding the extension reduced the ratio of gross load to maximum resistance to 2.9.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL53F04
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  • 36
    Publication Date: 2019-07-11
    Description: An experimental investigation has been conducted to determine the dynamic stability and control characteristics of a 0.13-scale free-flight model of the Convair XFY-1 airplane in test setups representing the setup proposed for use in the first flight tests of the full-scale airplane in the Moffett Field airship hangar. The investigation was conducted in two parts: first, tests with the model flying freely in an enclosure simulating the hangar, and second, tests with the model partially restrained by an overhead line attached to the propeller spinner and ground lines attached to the wing and tail tips. The results of the tests indicated that the airplane can be flown without difficulty in the Moffett Field airship hangar if it does not approach too close to the hangar walls. If it does approach too close to the walls, the recirculation of the propeller slipstream might cause sudden trim changes which would make smooth flight difficult for the pilot to accomplish. It appeared that the tethering system proposed by Convair could provide generally satisfactory restraint of large-amplitude motions caused by control failure or pilot error without interfering with normal flying or causing any serious instability or violent jerking motions as the tethering lines restrained the model.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL54B16A
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  • 37
    Publication Date: 2019-07-12
    Description: Static tests on a segment of a transpiration-cooled turbine rotor blade with a wire-cloth shell were conducted to determine the flow coefficients associated with some representative metering orifices. Average flow coefficients from 0.96 to 0.79 were obtained for orifices of 0.031 to 0.102 inch diameter.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-E53L30a
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  • 38
    Publication Date: 2019-07-11
    Description: An experimental investigation has been made in the Langley stability tunnel at low speed to determine the static longitudinal and lateral stability characteristics of a l/9-scale powered model of the Convair XFY-1 vertically rising airplane. Effects of thrust coefficient were investigated for the complete model and for certain components of the model. Effects of control deflections and of propeller-blade angle were investigated briefly for the complete model. Most of the tests were made through an angle-of-attack range from about -4 deg. to 29 deg, and the thrust-coefficient range was from 0 t o 0.7. In order to expedite distribution of these data to interested persons, no analysis of the data has been prepared for this report,
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL53B20
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  • 39
    Publication Date: 2019-07-11
    Description: An application of airfoil design methods was used to design series of related turbine-blade profiles to satisfy the conditions of inlet flow angle and turning angle encountered in the usual range of turbine operation. A series of blade profiles applicable to most turbine blading requirements and a secondary series with particular reference to impulse conditions were designed. Five blade sections from these series ranging in mean-line turning angles from 63 deg. to 120 deg. were tested in low-speed cascade tunnels. From low-speed test results optimum blade angles of attack were selected at each test condition. The induced angle and the deviation angle of the flow were determined from the low-speed data. If these angles are known for the solidity and inlet angle of an application, the necessary camber is specified. A method of predicting high-speed pressure distributions from low-speed cascade test results is presented to extend the usefulness of the low-speed data. Sample high-speed tests of two of the five blade sections were made at Mach numbers up to the critical value. The results indicated satisfactory flow conditions in all of the blade passages tested.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L53G15
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  • 40
    Publication Date: 2019-07-11
    Description: An investigation has been made in the Langley 9- by 12-inch supersonic blowdown tunnel to determine the effects of external-store location on the lift, drag, and pitching-moment characteristics of a 45 degree sweptback wing at Mach numbers of 1.41, 1.62, and 1.96. The spanwise, chordwise, and vertical location of a Douglas-Aircraft Company, Inc., store of fineness ratio 8.58 was systematically varied over the outer 60 percent of the wing semispan. A brief investigation of strut sweep angle was also made. The test Reynolds number based on the wing mean aerodynamic chord ranged from 1.3 x 10(exp 6) to 1.5 x 10(exp 6).
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L52J27
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  • 41
    Publication Date: 2019-07-11
    Description: The hydrodynamic characteristics of a preliminary design of the Martin XP6M-1 flying boat have been determined. Longitudinal stability during take-off and landing, resistance of the complete model, and behavior during taxiing and landing in rough water are presented.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL53K06
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  • 42
    Publication Date: 2019-07-11
    Description: Preliminary results of one phase of a control-motion study program involving several jet fighter-type airplanes are presented in time-history form and are summarized as maximum measured quantities plotted against indicated airspeed. The results pertain to approximately 1,000 maneuvers performed by a Republic F-84G jet-fighter airplane during squadron operational training. The data include most tactical maneuvers of which the F-84G airplane is capable. Maneuvers were performed at pressure altitudes of 0 to 30,000 feet with indicated airspeeds ranging from the stalling speed to approximately 515 knots.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L53C27
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  • 43
    Publication Date: 2019-08-28
    Description: A systematic research program is being carried out in the Langley high-speed 7- by 10-foot tunnel to determine the aerodynamic characteristics of various arrangements of the component parts of research-type airplane models, including some complete model configurations. Data are being obtained on characteristics in pitch, sideslip, and during steady roll at Mach numbers from 0.40 to about 0.95. This paper presents results which show the effect of taper ratio on the aerodynamic characteristics in sideslip of wing-fuselage combinations having wings with a sweep of 45 degrees at the quarter-chord line, an aspect ratio of 4, and a NACA 65A006 airfoil section.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L53B25a
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  • 44
    Publication Date: 2014-07-15
    Description: A cascade of 65-(12)10 compressor blades was tested at one geometric setting over a range of inlet Mach number from 0.12 to 0.89. Two groups of data are presented and compared: the first from the cascade operating conventionally with no boundary-layer control, and the second with the boundary layer controlled by a combination of upstream slot suction and porous-wall suction at the blade tips. A criterion for two-dimensionality was used to specify the degree of boundary-layer control by suction to be applied. The data are presented and an analysis is made to show the effect of Mach number on turning angle, blade wake, pressure distribution about the blade profile and static-pressure rise. The influence of boundary-layer control on these parameters as well as on the secondary losses is illustrated. A system of correlating the measured static-pressure rise through the cascade with the theoretical isentropic values is presented which gives good agreement with the data. The pressure distribution about the blade profile for an inlet Mach number of 0.21 is corrected with the Prandtl-Glauert, Karman-Tsien, and vector-mean velocity - contraction coefficient compressibility correction factors to inlet Mach numbers of 0.6 and 0.7. The resulting curves are compared with the experimental pressure distributions for inlet Mach numbers of 0.6 and 0.7 so that the validity of applying the three corrections can be evaluated.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-TN-2649
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  • 45
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1952) nr.16 p.165
    Publication Date: 2013-03-01
    Description: When revising the genera of Indo-Australian and Papuan Tortricidae (1939) the author was very much in doubt as to the systematic position of the genus Diactenis Meyrick, 1907, referred before to the Tortricidae. It did not fit in that family, neither could it be successfully transferred to any other Tortricoid family known. Through lack of further data the author decided at last to transfer Diactenis to the family Chlidanotidae; the necessity of its removal from the Tortricidae being only too evident. This decision, however, was not very happy, as Diactenis was neither at its proper place in the Chlidanotidae. In the same year (1939) the late T. Bainbrigge Fletcher suggested to the author (in litt.) to erect for Diactenis a new family. Although this seemed a reasonable solution, we esteemed such an action to be premature, our information on the possible congeners of Diactenis being insufficient at that time. Instead, however temporarily, Diactenis was transferred back to the Tortricidae; but at the same time attention was drawn to the close correlation of that genus with two others (1941). Soon afterwards still more new forms of the Diactenis relationship continued coming to our notice, and the conception of this new family began to take shape. It materialized after our study of the excellent collection of Microlepidoptera, brought together by our lamented friend, the late Dr. L. J. Toxopeus, during the Third Archbold Expedition to New Guinea. The results of this study will be published soon. Meanwhile we are satisfied that the information collected during these twelve years is entirely sufficient for carrying into effect the so long
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 46
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1952) nr.24 p.259
    Publication Date: 2013-03-01
    Description: A study of the collection of Dermaptera in the Rijksmuseum van Natuurlijke Historie at Leiden has been made by the author during the years 1942 and 1943, but publication of the results had to be postponed for several years on account of various difficulties arising during and since the war. These investigations yielded some interesting results, including the descriptions of several new species. It is intended to publish these descriptions in the near future after a study of the literature of the group that has appeared since 1943. Of the subfamily Diplatyinae the material of the Leiden Museum contains specimens of two forms that proved to belong to hitherto undescribed species. Together with other representatives of this subfamily these specimens were sent to Dr. W. D. Hincks of the Manchester Museum, for comparison with the material that formed the basis for his nearly completed revision of the group. Of the two forms referred to above, one appeared to be conspecific with a species to be described by Dr. Hincks in the near future, the other is described in the present paper, in order that notes on this species may be incorporated into the revision of the group. Diplatys sumatranus nov. spec. 1 ♂, Air Njuruk, Dempu, Sumatra, 1400 m, VIII 1916, coll. E. Jacobson. The present specimen is small and slender, of the usual general appearance in this genus (see fig. 1). Colouration: the head and the prozona of the pronotum are castaneous; the same colour, though less dark generally, is shown by the median part of the metazona, the elytra, a band along the outer margins of the wing-scales, Fig. 1. Diplatys sumatranus nov. spec. af habitus of male, and end of abdomen in lateral
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 47
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1952) nr.23 p.251
    Publication Date: 2013-03-01
    Description: In the course of the later years a rather large number of specimens of various groups of insects from New Guinea were among the acquisitions of the Rijksmuseum van Natuurlijke Historie. Shortly after the war the collections made by Professor H. Boschma, during his visit to the Wissel Lakes in 1939 as the zoologist of the expedition organized by the Royal Netherlands Geographical Society (Koninklijk Nederlandsch Aardrijkskundig Genootschap), arrived safely from Bogor (Java) where they had to stay during the German occupation of the Netherlands. Quite recently we obtained the first captures made by Dr. L. D. Brongersma in various places in and near New Guinea. From both collections a number of new and interesting Heteroptera is to be described. A few Oncomerini, belonging to the genera Lyramorpha and Agapophyta, are the subject of the present note. Lyramorpha Subgenus Lyrodes Of the subgenus Lyrodes two new species were collected at and near the Wissel Lakes. The first, which I will name Lyramorpha (Lyrodes) edulis nov. spec.*) (figs. 1-2), shows no definite spot or patch on the corium; the basal corners of the scutellum are yellowish, medially from this yellow spot a distinct dark point is to be seen, except in specimens that are more or less immature. The general colour is more or less castaneous, with inVentral views of the ultimate abdominal segments of: fig. I, Lyramorpha (Lyrodes) edulis ♂ ; fig. 2, Lyramorpha (Lyrodes) edulis ♀ ; fig. 3, Lyramorpha (Lyrodes) plagifer ♂ ; fig. 4, Lyramorpha (Lyrodes) plagifer ♀ ; fig. 5, Lyramorpha (Diploxiphus) maculifer ♂ ; fig. 6, Lyramorpha (Diploxiphus) maculifer ♀.
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 48
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1952) nr.20 p.225
    Publication Date: 2013-03-01
    Description: The present paper constitutes a report on the Machilidae and Lepismatidae collected by Dr. C. O. van Regteren Altena in the Canary Islands in the spring of 1947. We are much obliged to Dr. van Regteren Altena for allowing us to study these interesting specimens. The first notice on Thysanura from the Canary Islands seems to be the mentioning of Machilis maritima by Lucas (1836-44). Unfortunately it is quite impossible nowadays to identify that species as understood by Lucas. Ridley (1881) mentions three species from the Canary Islands, viz., Lepisma saccharina L., from Tenerife and Gran Canaria; Lepisma mauritanica Lucas, from Las Palmas (Gran Canaria) and Lepisma eatonii Ridley, from Tenerife. L. saccharina has apparently not been found again on the Islands; anyhow we do not see any reason to doubt its presence there. Lepisma mauritanica, actually included in the genus Ctenolepisma, is a species that is rare as well as very difficult to identify; Ridley's specimens were most probably nothing else but dark Ctenolepisma lineata, a species common in the Islands. Finally Lepisma eatonii, whose correct name should be Ctenolepisma lineata eatonii, is nothing more than a colour form of Ctenolepisma lineata, which may not deserve even subspecific rank. Escherich (1905) also mentions Ctenolepisma lineata eatonii from Tenerife. Silvestri (1940) gives the first record for Lepisma myrmecobia Silvestri from the Islands (Gran Canaria and Tenerife). Wygodzinsky (1941) described Dilta insulicola from Tenerife. In the present paper an additional species of Dilta, Dilta altenai sp. n. is described from Tenerife, and several of the formerly known species of
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 49
    facet.materialart.
    Unknown
    In:  Zoologische Verhandelingen (0024-1652) vol.16 (1952) nr.1 p.1
    Publication Date: 2013-03-01
    Description: The Oriental bees of the genus Ceratina Latr. are difficult to identify. Until now our knowledge of these insects consisted mainly of a considerable number (about 90) of isolated descriptions, scattered through several scientific journals. Most of these descriptions are based on colour characters and although these are certainly not without taxonomic value, they must be used with great care on account of their intra-specific variability. The structural and sculptural characters which are much more reliable for distinguishing the species have thus far not received sufficient attention. There exist a few keys, dealing with the species occurring in certain parts of the region, but none of these contains more than 11 species and the characters used are often of doubtful taxonomic value. An attempt to identify a large number of species collected in Indonesia, mainly in Java, by Dr. and Mrs. Lieftinck, my wife and myself, soon demonstrated the necessity of a revision of the Ceratina species described from this and other parts of the Oriental region. It would have been completely impossible to recognize the majority of these species with sufficient certainty from their descriptions. Fortunately I had an opportunity to study much authentic material. In September 1951 I examined the types of several species described by Smith, Cameron, and Cockerell in the collections of the British Museum (Natural History) and the Oxford University Museum ; some additional types, preserved in the Rothney collection in the latter Museum, were kindly sent to me for study at a later date. The U.S. National Museum sent me a very interesting collection of oriental Ceratina, containing several species identified by Cockerell as well
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 50
    Publication Date: 2019-07-11
    Description: Tests have been made at the Langley Aeronautical Laboratory on a 6000-horsepower propeller dynamometer installed at a ground test facility to determine the effect of a half-scale model of the Wright Aeronautical Development Center 30,000-horsepower whirl rig upon the aerodynamic characteristics of a three-blade NACA 10-(3)(062)-045 propeller. The model of the whirl rig was mounted in front of the 6000-horsepower propeller dynamometer. Static propeller tests were made for 0deg, 5deg, 10deg, 15deg, and 20deg blade angles over a range of rotational speeds from 600 to 2200 rpm in 100-rpm increments. Measurements were made of propeller thrust and torque, stresses in the propeller blades, and static and total pressures over the surface of the model. Propeller thrust and torque were increased up to 33 percent by the presence of the model of the whirl rig, but the average increase was from 5 to 10 percent. Blade vibratory stresses were small.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL52F20
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  • 51
    Publication Date: 2019-07-11
    Description: An elementary type of analysis has been used to determine the amount of wing tip that must be severed to produce irrevocable loss of control of a B-29 airplane. The remaining inboard structure of the Boeing B-29 wing has then been analyzed and curves are presented for the estimated reduction in structural strength due to four general types of damage produced by rod-type warhead fragments. The curves indicate the extent of structural damage required to produce a kill of the aircraft within 10 seconds.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L52H01A
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  • 52
    Publication Date: 2019-07-12
    Description: The stator-blade angles in the twelfth through fifteenth stages of a 16-stage axial-flow compressor were increased 3O. The over-all performance of this modified compressor is compared to the performance of the compressor with original blade angles. The matching characteristics of the modified compressor and a two-stage turbine were obtained and compared to those of the compressor with original blade angles and the same turbine.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-E52A10
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  • 53
    Publication Date: 2019-07-11
    Description: As part of a program to determine the feasibility of using a fighter airplane as a parasite in combination with a Consolidated Vultee RB-36 for long-range reconnaissance missions (project FICON), an experimental investigation has been made in the Langley free-flight tunnel to determine the dynamic stability and control characteristics of a 1/17.5-scale model of a Chance Vought F7U-3 airplane in several tow configurations. The investigation consisted of flight tests in which the model was towed from a strut in the tunnel by a towline and by a direct coupling which provided complete angular freedom. The tests with the direct coupling also included a study of the effect of spring restraint in roll in order to simulate approximately the proposed full-scale arrangement in which the only freedom is that permitted by the flexibility of the launching and retrieving trapeze carried by the-bomber. For the tow configurations in which a towline was used (15 and 38 feet full scale), the model had a very unstable lateral oscillation which could not be controlled. The stability was also unsatisfactory for the tow configuration in Which the model was coupled directly to the strut with complete angular freedom. When spring restraint in roll was added, however, the stability was satisfactory. The use of the yaw damper which increased the damping in yaw to about six times the normal value of the model appeared to have no appreciable effect on the lateral oscillations in the towline configurations, but produced a slight improvement in the case of the direct coupling configurations. The longitudinal stability was satisfactory for those cases in which the lateral stability was good enough to permit study of longitudinal motions.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL53D07
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  • 54
    Publication Date: 2019-07-11
    Description: The aerodynamic characteristics in pitch of the Army Ordnance Corps T205 3.5-inch HEAT rocket with various head designs and one fin modification have been determined at velocities of 500, 700 and 900 feet per second in the Langley high-speed 7- by 10-foot tunnel. The results presented are those of the full-scale model. Comparison of results obtained at 500 feet per second shows, in general, that for changes on the forward portion of the head the missile configurations having the greatest stability - most rearward center-of-loads location - were those having the highest drag. However, very limited comparisons indicate that the shape of the rear position of the head may be an important factor in reducing the drag and increasing the restoring moments. Generally, large increases in drag were noted for the various head designs with an increase in Mach number from 0.62 to 0.82. Pitching-moment-curve slopes increased with Mach number on all models except those having reasonably well-faired forward sections. These models showed a decrease in stability with increases in Mach number.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL52G15
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  • 55
    Publication Date: 2019-07-11
    Description: Preliminary results of one phase of a control-motion study program are presented in the form of plots of load factor.and angular acceleration against indicated airspeed and of time histories of several measured quantities. The results were obtained from 197 maneuvers performed by an F-86A jet-fighter airplane during normal squadron operational training. Most of the tactical maneuver8 of which the F-86A is capable were performed at pressure altitudes ranging from 0 to 32,000 feet and at indicated airspeeds ranging from 95 to 650 miles per hour.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L52C19
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  • 56
    Publication Date: 2019-07-12
    Description: Force characteristics determined from tank tests of a 1/5.78 scale model of a hydro-ski-wheel combination for the Grumman JRF-5 airplane are presented. The model was tested in both the submerged and planing conditions over a range of trim, speed, and load sufficiently large to represent the most probable full-size conditions.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SLS2B28
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  • 57
    Publication Date: 2019-07-12
    Description: An investigation was conducted in the Ames 12-foot pressure wind tunnel to determine the effect of an operating propeller on the aerodynamic characteristics of a l/l9-scale model of the Lockheed XFV-1 airplane, Several full-scale power conditions were simulated at Mach numbers from 0.50 to 0.92; the.Reynolds number was constant at 1,7 million. Lift, longitudinal force, pitch, roll, and yaw characteristics, determined with and without power, are presented for the complete model and for various combinations of model components, Results of an investigation to determine the characteristics of the dual-rotating propeller used on the model are given also,
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SA52E06
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  • 58
    Publication Date: 2019-07-12
    Description: The stator-blade angles in the first four stages of a 16-stage axial-flow compressor were increased in order to decrease the angles of attack of these stages, and thereby to improve part-speed performance. The performance of this modified compressor was compared with that of the same compressor with original blade angles.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-E52B15
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  • 59
    Publication Date: 2019-08-14
    Description: An impulse-momentum method for determining impact conditions for landing gears in eccentric landings is presented. The analysis is primarily concerned with the determination of contact velocities for impacts subsequent to initial touchdown in eccentric landings and with the determination of the effective mass acting on each landing gear. These parameters determine the energy-absorption requirements for the landing gear and, in conjunction with the particular characteristics of the landing gear, govern the magnitude of the ground loads. Changes in airplane angular and linear velocities and the magnitude of landing-gear vertical, drag, and side impulses resulting from a landing impact are determined by means of impulse-momentum relationships without the necessity for considering detailed force-time variations. The effective mass acting on each gear is also determined from the calculated landing-gear impulses. General equations applicable to any type of eccentric landing are written and solutions are obtained for the particular cases of an impact on one gear, a simultaneous impact on any two gears, and a symmetrical impact. In addition a solution is presented for a simplified two-degree-of-freedom system which allows rapid qualitative evaluation of the effects of certain principal parameters. The general analysis permits evaluation of the importance of such initial conditions at ground contact as vertical, horizontal, and side drift velocities, wing lift, roll and pitch angles, and rolling and pitching velocities, as well as the effects of such factors as landing gear location, airplane inertia, landing-gear length, energy-absorption efficiency, and wheel angular inertia on the severity of landing impacts. -A brief supplementary study which permits a limited evaluation of variable aerodynamic effects neglected in the analysis is presented in the appendix. Application of the analysis indicates that landing-gear impacts in eccentric landings can be appreciably more severe than impacts in symmetrical landings with the same sinking speed. The results also indicate the effects of landing-gear location, airplane inertia, initial wing lift, side drift velocity, attitude, and initial rolling velocity on the severity of both initial and subsequent landing-gear impacts. A comparison of the severity of impacts on auxiliary gears for tricycle and quadricycle configurations is also presented.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-TN-2596
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  • 60
    Publication Date: 2018-06-11
    Description: The damping in roll and rolling effectiveness of two models of a missile having cruciform, triangular, interdigitated wings and tails have been determined through a Mach number range of 0.8 to 1.8 by utilizing rocket-propelled test vehicles. Results indicate that the damping in roll was relatively constant over the Mach umber range investigated. The rolling effectiveness was essentially constant at low supersonic speeds and increased with increasing mach numbers in excess of 1.4 over the Mach number range investigated. Aeroelastic effects increase the rolling-effectiveness parameters pb/2V divided by delta and decrease both the rolling-moment coefficient due to wing deflection and the damping-in-roll coefficient.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L51D16
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  • 61
    Publication Date: 2014-07-15
    Description: The empirical relation between the induced velocity, thrust, and rate of vertical descent of a helicopter rotor was calculated from wind tunnel force tests on four model rotors by the application of blade-element theory to the measured values of the thrust, torque, blade angle, and equivalent free-stream rate of descent. The model tests covered the useful range of C(sub t)/sigma(sub e) (where C(sub t) is the thrust coefficient and sigma(sub e) is the effective solidity) and the range of vertical descent from hovering to descent velocities slightly greater than those for autorotation. The three bladed models, each of which had an effective solidity of 0.05 and NACA 0015 blade airfoil sections, were as follows: (1) constant-chord, untwisted blades of 3-ft radius; (2) untwisted blades of 3-ft radius having a 3/1 taper; (3) constant-chord blades of 3-ft radius having a linear twist of 12 degrees (washout) from axis of rotation to tip; and (4) constant-chord, untwisted blades of 2-ft radius. Because of the incorporation of a correction for blade dynamic twist and the use of a method of measuring the approximate equivalent free-stream velocity, it is believed that the data obtained from this program are more applicable to free-flight calculations than the data from previous model tests.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-TN-2474
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  • 62
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1951) nr.13 p.129
    Publication Date: 2013-03-01
    Description: Records of cave-dwelling Lepidoptera are scarce in comparison with those in other orders of Insects, e.g., Coleoptera, of which even a whole subfamily (Silphidae, Bathysciinae) is in a most remarkable way adapted to this peculiar habitat. In the group of the so-called Microlepidoptera we could find examples of some eight species only, belonging to different families. Apparently none of them is a true cave-dweller, i. e., a permanent resident of caves and really adapted to life in total darkness. Crypsithyris spelaea Meyrick, 1908 (Tinaeidae) only has been regarded as an exception. This species has been described from a large cave in Moulmein, Burma, and originally was reported as "being practically bleached or colourless", but with normally developed eyes and wings (Meyrick, 1908, p. 399). Later on better material has been collected at the same locality, and this time the moth appeared to be not quite colourless (Meyrick, 1916, pp. 602-603). It remains uncertain, therefore, whether there is question of any adaptation to cave-life and whether this species can be regarded as an "obligate cavernicole,, insect, the more so as larvae of closely allied species of this genus have been found living in the open, in portable cases on lichens covering rocks. Furthermore we could find reference to three species of the genus Tinaea: T. antricola Meyr., 1924, and T. pyrosoma Meyr., 1924, both from Siju Caves, Assam, and T. palaechrysis Meyr., 1929, from Batu Caves, Selangor (Malaya). Of the latter was said that it "belongs to the typically unicolorous yellow group, but has probably acquired fuscous colouring as an adaptation to cave life; it may therefore be a true cave-dweller, possibly restricted to these particular caves" (Meyrick, 1929, p. 375). Afterwards, however, Dam-
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 63
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1951) nr.15 p.149
    Publication Date: 2013-03-01
    Description: I. Grouping of European species of the genus Astata Latr. It is not my intention to anticipate in this paper a subgeneric division of the genus Astata 1). For the purpose of such division, it would be necessary to investigate more non-European material than at present is at my disposal. But at first view it seems to me that the European species may be divided into four distinct groups, which may be separated with the key given below. Two of the proposed groups (the stigma-group and the tricolor-group) form part of the subgenus Dryudella Spinola, as this subgenus has generally been understood; nevertheless, the differences between these two groups, namely in the shape of the clypeus and, in the females, in the habitus, seem to justify separating them; although, investigation of allied non-European species might make it necessary to adapt or to modify the key to the groups. Eventually, the possibility that non-European intermediate forms will make the separations untenable cannot be absolutely excluded. A decision about the taxonomic rank of the proposed groups, therefore, must be postponed. Spinola (1843, P- 135), erecting the genus or subgenus Dryudella ("une nouvelle coupe, qu'on appellera genre ou sous-genre, selon les principes qu'on aura adoptes dans la nomenclature binominale"), based the "nouvelle coupe" on the wing venation of "Dimorpha cincta Perris" and separated it from "Dimorpha" 1) "par la troisieme cubitale, lunulee comme dans les "Lyrops" 2) et par la premiere nervure recurrente, qui s'anastomose avec la nervure transversale qui separe la premiere de la seconde cubitale". However, in these critical features, Spinola was incorrect in several respects. Even excluding stigma and its near allies from Dryudella (Spinola himself never
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
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  • 64
    Publication Date: 2019-07-11
    Description: A flight investigation of a 1/7-scale rocket-powered model of the XF10F Grumman XFl0F airplane in the swept-wing configuration has been made. The purpose of this test was to determine the static longitudinal stability, damping in pitch, and longitudinal control effectiveness of the airplane with the center of gravity at 20 percent of the wing mean aerodynamic chord. Only a small amount of data was obtained from the test because, immediately after booster separation at a Mach number of 0.88, the configuration was directionally unstable and diverged in sideslip. Simultaneous with the sideslip divergence, the model became longitudinally unstable at 3 degree angle of attack and -6 degree sideslip and diverged in pitch to a high angle of attack. During the pitch-up the free-floating horizontal tail became unstable at 5 degree angle of attack and the tail drifted against its positive deflection limit.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL52I25
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  • 65
    Publication Date: 2019-07-11
    Description: An investigation of a 1/24- scale dynamically similar model of the Douglas C-124 airplane was made to determine the ditching characteristics and proper technique for ditching the airplane. Various conditions of damage, landing attitude, flap setting, and speed were investigated. The behavior of the model was determined from visual observations, motion- picture records, and time-history deceleration records. The results of the investigation are presented in table form, photographs, and curves. It was concluded on the basis of results from model tests with scale-strength bottoms (equivalent to 1150 pounds per square foot, full scale) that the airplane should be ditched at a medium nose-high landing attitude (near 7deg) with flaps full down. The airplane will probably make a smooth run with considerable damage resulting to the fuselage bottom just forward of the wing, but it is not likely that the water inflow will be overwhelming to personnel provided they are not in the belly compartment. Longitudinal decelerations in calm water will be about 2 1/2g and the landing run will be about four fuselage lengths.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL51F20
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  • 66
    Publication Date: 2019-07-12
    Description: The present paper presents the results of a brief investigation made to determine the effectiveness of a proposed emergency spin-recovery device to be used during demonstration spins of the Northrop XF -89 airplane. The proposed device makes use of split-type ailerons deflected +/-60deg on the outboard wing (left wing in a right spin). Tests made on a model which represented the airplane to a scale of 7 indicated that, if an uncontrollable spin is obtained in the design gross--weight loading, the device is not sufficiently effective to insure recovery,
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL-51H24
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  • 67
    Publication Date: 2019-07-12
    Description: As part of a study of means of airspeed measurement at transonic speeds the use of static orifices located ahead of the wing tip has been investigated for possible application to service or research airspeed installations. The local static pressure and local Mach number have been measured at a distance of 1 tip chord ahead of the wing tip of a model of a swept-wing fighter airplane at true Mach numbers between 0.7 and 1.08 by the NACA wing-flow method. All measurements were made at or near zero lift. The local Mach number was found to be essentially equal to the true Mach numbers less than about 0.90. The local Mach number was found to be about 0.97 at a true Mach number of 0.95, and to be about 1.04 at a true Mach number of 1.08. The local Mach number provided a reasonable sensitive measure of true Mach number except for a restricted region near a true Mach number of 1.0 where the local Mach number did not change appreciably with true Mach number. The linear theory was found to predict qualitatively the effect of the fuselage on the static pressure ahead of the wing time but gave a reasonable prediction of the effect of the wing on the static pressure only at Mach numbers below 0.95.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-L50L28
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  • 68
    Publication Date: 2019-07-11
    Description: Two theoretical procedures are developed for designing asymmetric supersonic nozzles for which the calculated exit flow is nearly uniform over a range of Mach numbers. One procedure is applicable at Mach numbers less than approximately 3. This approach yields, without iteration, a nozzle for which the calculated exit flow is uniform at two Mach numbers and, with proper design, is nearly uniform at Mach numbers between, slightly above, and slightly below these two. The use of an inclined and curved sonic line is an essential feature of this approach, The second procedure requires iteration and is used far designs at Mach numbers exceeding 3. Although it is not a necessary feature, an inclined and curved sonic line is also used in this procedure. In both approaches the flow field dawn stream of the sonic line is determined using the method of characteristics.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-A51A19
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  • 69
    Publication Date: 2019-07-11
    Description: A tank investigation has been conducted on a 1/8-size powered dynamic model of the Grumman JRF-5 airplane equipped with twin hydro-skis. The results of tests using two types of skis are presented: one had vertical sides joining the top surface to the chine; the other had the top surface faired to the chine to eliminate the vertical sides. Both configurations had satisfactory longitudinal stability although the model had a slightly greater stable elevator range available when the skis without the vertical sides were attached. Free model tests indicated no instability present when one ski emerged before the other. Considerable excess thrust was available at all speeds with either type of skis. A hump gross load-resistance ratio of 3.37 was obtained with the skis with the vertical sides and 3.53 with the other skis. Landing behavior in smooth water with yaw up to 15deg and roll up to 15deg in opposite directions was satisfactory with either type of skis.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA RM-SL52D17
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  • 70
    Publication Date: 2019-07-11
    Description: A tank investigation has been conducted of a 1/10-size powered-dynamic model of the Edo model 142 hydra-ski research airplane. The results of tests of two configurations are presented: One included a large ski and a ski well; the other, a small ski without a well. Water take-offs would be possible with the available thrust for either configuration: however, the configuration with the large ski emerged sooner and had less resistance from ski emergence until take-off. Longitudinal stability and landing behavior in smooth water were satisfactory for both configurations. Some alteration to the design of the tail would be desirable in order to reduce the spray loads.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL51I24
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  • 71
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2019-08-15
    Description: It has been shown that the circumferential pressure distributions for the inclined body and circular cylinder deviate from their respective theoretical inviscid distributions on the lee or downstream side in the same manner. With the aid of visual flow techniques, it has been shown that there is a shedding of vortices within the crossflow field of the inclined body. It has also been found that the vortex configuration depoends to a large extent on the shape of the nose of the body. To illustrate this, vapor screen pictures were made and results are discussed.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA Conference on Aerodynamic Design Problems of Supersonic Guided Missiles; Oct 02, 1951 - Oct 03, 1951; Moffett Field, CA; United States|Aerodynamic Characteristics of Bodies at Supersonic Speeds: A Collection of Three Papers; 31-44; NACA-RM-A51J25
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  • 72
    Publication Date: 2014-07-15
    Description: The autorotative performance of an assumed helicopter was studied to determine the effect of inoperative jet units located at the rotor-blade tip on the helicopter rate of descent. For a representative ramjet design, the effect of the jet drag is to increase the minimum rate of descent of the helicopter from about 1,OO feet per minute to 3,700 feet per minute when the rotor is operating at a tip speed of approximately 600 feet per second. The effect is less if the rotor operates at lower tip speeds, but the rotor kinetic energy and the stall margin available for the landing maneuver are then reduced. Power-off rates of descent of pulse-jet helicopters would be expected to be less than those of ramjet. helicopters because pulse jets of current design appear to have greater ratios of net power-on thrust to power-off, drag than currently designed rain jets. Iii order to obtain greater accuracy in studies of autorotative performance, calculations in'volving high power-off rates of descent should include the weight-supporting effect of the fuselage parasite-drag force and the fact that the rotor thrust does not equal the weight of the helicopter.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-TN-2154
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  • 73
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1950) nr.7 p.67
    Publication Date: 2013-03-01
    Description: On trouvera ici l'étude d'une partie des Hepialidae du Musée de Leiden que le Dr. van Regteren Altena a bien voulu nous confier pour étude, ce dont le remercions vivement. Nous y avons ajouté l'étude de quatre espèces du British Museum (N.H.) et une du Museum de Paris. HÉPIALIDES DE LA NOUVELLE GUINÉE On connait quelques Hépiales décrites de Nouvelle Guinée. Elles appartiennent au magnifique genre Oenetus H.S. et au genre Oxycanus Walk, (s.l.). On trouvera ici l'étude de quelques espèces appartenant à ce dernier genre. Grace à l'amabilité de Mr. J. D. Bradley du British Museum (N.H.), que nous remercions, les quatre espèces décrites par Joicey et Talbot (1917) ont pu etre étudièes. Paraoxycanus n. gen. Ce nouveau genre, très proche du genre Oxycanus Walk, ne comprend jusqu'à présent, à notre connaissance, que quelques Hépiales néo-guinéennes classées jadis dans le genre Porina Walk. Tindale (1936) a montré que ce dernier nom était préoccupé et que, de plus, il était synonyme d'Oxycanus Walk. L'espèce type de ce genre a été fixée par Kirby (1892) comme étant australis Walk. Ayant trouvé que l'armure génitale male des espèces étudiées était différente de celle d'australis Walk. nous devons créer ce genre. On pourra comparer les figures 7 et 8. La nervation est la meme que celle du genre Oxycanus Walk. La patte prothoracique porte un strigil. Les antennes ne sont pas fortement bipectinees, mais seulement avec un petit bouquet de soies a l'apex de chaque article. Enfin dans rarmure genitale male il existe une nette difference dans le vinculum, dans les relations de celui-ci avec la membrane mtersegmentaire
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 74
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1950) nr.4 p.39
    Publication Date: 2013-03-01
    Description: The genus Podolestes, as far as at present known, is confined to the Malaysian subregion of the Indo-Australian Archipelago. Descriptions and drawings of structural details of four species are to be found in two of the writer's previous papers on Malaysian dragonf lies, viz.: New and little known Odonata of the Oriental and Australian Regions. Treubia, 15, 1935: 177-183, fig. 1-3. Descriptions and records of South-East Asiatic Odonata (II). Ibid. 17, 1940: 347-350, fig. 4-5. The species of Podolestes have been found in marshes and along muddy creeks flowing through wooded areas in low country. Owing to their retiring habits the insects are but seldom encountered and all species are rare in collections. Little or nothing is known of their life-histories, and the larva is still unknown. The six known members of the genus, two of which are here described for the first time, may be distinguished by the following Key to the species. 1. Dorsum of thorax uniform metallic bronzy black. Labrum, mandibles and genae shiny black. Ante-alar triangles bronzy-black, unmarked. Nervure Ac situated much nearer Ax2 than Ax1; nervure Ab complete, meeting Ac at the wing-margin. Quadrilateral short, markedly widened distally, costal and distal sides approximately equal in length in fore wing. Three to four postquadrangular antenodal cells. Male anal appendages of slender build, blackish in colour; superior pair a trifle longer than the inferiors; apex of inf. app. expanded, truncated and slightly notched 2. —. Dorsum of thorax with two pairs of light-coloured spots on mesepisternum, and sides with an oblique band extending from below the spiracle upwards as far as the dorsal
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 75
    facet.materialart.
    Unknown
    In:  Zoologische Verhandelingen (0024-1652) vol.11 (1950) nr.1 p.1
    Publication Date: 2013-03-01
    Description: CONTENTS Introduction............... 3 Systematic survey of the Limacidae of the central and western Canary Islands 5 Biogeographical notes on the Limacidae of the Canary Islands . . . . 21 Alphabetical list of the persons who collected or observed Limacidae in the Canary Islands.............. 31 Literature............... 32 INTRODUCTION In the spring of 1947 I was so fortunate as to join for some 9 weeks the Danish Zoological Expedition to the Canary Islands. During my stay I collected materials for the Rijksmuseum van Natuurlijke Historie at Leiden, paying special attention to the land- and freshwater Mollusca. This paper contains the first results of the examination of the Mollusca collected. My Danish friends Dr. Gunnar Thorson and Dr. Helge Volsøe generously put at my disposal the non-marine Mollusca they collected during their stay in the Canaries. When the material has been worked up, duplicates will be deposited in the Zoological Museum at Copenhagen. I am indebted to several persons who helped me in various ways in the investigations here published. Prof. Dr. N. Hj. Odhner (Stockholm) very kindly put at my disposal a MS list of all the Mollusca of the Canary Islands and their distribution, which he had compiled for private use. Mr. Hugh Watson (Cambridge) never failed to help me by examining or lending specimens, and in detailed letters gave me the benefit of his great experience. During my stay in Paris in March 1950 Dr. G. Ranson and Dr. A. Franc put at my disposal for examination the Canarian slugs present in the Muséum
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 76
    facet.materialart.
    Unknown
    In:  Zoologische Mededelingen (0024-0672) vol.31 (1950) nr.6 p.63
    Publication Date: 2013-03-01
    Description: Part of the butterfly collection of Mr. P. Zondervan, who died in a Japanese camp, was saved from destruction during the Japanese occupation and the post-war troubles and finally came into my hands. The material is for the greater part still in an excellent condition and contains many interesting forms. The number of specimens is small, as it was Mr. Zondervan's habit to mount only one pair of any new species he collected. The bulk so remained in papers and these all got lost. Here follows an account of some interesting Pieridae. Appias (paulina) urania (Wall.) Tachyris urania, Wallace, "Eastern Pieridae", Trans. ent. Soc. 6 (3) 3 (1867), Tondano, mountains of N. Celebes (♂). Appias urania, Martin, D. ent. Zeits. Iris, 91, 1919. 1 ♂, Tondano, 17.7.1939, 1 ♀, Tondano, 9.1937; 1 ♂, var. albata Hopff., Tondano, 22.12.1939. The ♀ seems to be very rare, though it shows up in rather good numbers in other places of the paulina area in the favourable season, which is at the end of the wet monsoon. It would have been waste of paper to mention these captures, were it not that Mr. Zondervan captured another ♂ specimen of the paulina complex which is so deviating from the above that anybody first seeing it would conceive it as belonging to a distinct species. It represents the leis (Hbn.) group of paulina (Cram.) in the Celebes district, just as urania Wall., together with some local races from the Lesser Sunda Is., is the general representative in the Archipelago. In other words, there has been some overlapping in Celebes, and one more species duplex must be added to the
    Keywords: 42.75
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • 77
    Publication Date: 2019-07-11
    Description: Investigations have been conducted to determine by means of total-pressure surveys the boundaries of single and twin jets discharging through convergent nozzles into quiescent air. The jet boundaries for the region from the nozzle outlets to a station 6 nozzle diameters downstream are presented for nozzle pressure ratios ranging from 2.5 t o 16.0 and for twin-Jet nozzle center-line spacings ranging from 1.42 to 2.50 nozzle diameters. The effects of these parameters on the interaction of twin Jets are discussed. In order to ascertain the utility of the results for other than the test conditions, the effects of jet temperature, Reynolds number, and humidity on the pressure boundaries have been briefly investigated. The result indicate that for a jet of 2.6 the pressure boundaries are slightly smaller than those of corresponding unheated jets and that the effects of Reynolds number and humidity are negligible.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-E50E03a
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  • 78
    Publication Date: 2019-07-11
    Description: At the request of the Air Materiel Command, an investigation was made in the Langley free-flight tunnel to determine the longitudinal stability and control characteristics of models coupled together in a tandem configuration for aerial refueling similar to one proposed by the Douglas Aircraft Company, Inc. Static force tests were made with 1/20-scale models of the B-29 and F-80 airplanes to determine the effects of rigidly coupling the airplanes together. The Douglas configuration differs from the rigid configuration tested in that it provides for some freedom in pitch and vertical displacement. The force tests showed that, for the bomber alone, the aerodynamic center was 0.21 mean aerodynamic chord behind the center of gravity (stable) but that for the tandem configuration with rigid coupling the aerodynamic center was 0.28 mean aerodynamic chord forward of the center of gravity of the combination (unstable). This reduction in stability was caused by the downwash of the bomber on the fighter. The pitching moment produced by elevator deflection of the bomber was reduced approximately 50 percent by addition of the fighter. Some recent flight tests made in the free-flight tunnel on models in a similar tandem configuration indicated that, with a hinged coupling permitting freedom in pitch, the stability of the combination was better than that obtained with a rigid coupling and was about the same as that for the bomber alone.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL50E01
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  • 79
    Publication Date: 2019-07-11
    Description: An experimental investigation of the variation of aileron rolling effectiveness and total drag with Mach number has been made using 1/6-scale rocket-propelled models of the Bell MX-776. Three models having constant-chordwise-thickness full-span aileron at approximate deflections of 2 deg, 5 deg, and 15 deg have been flown. Positive control effectiveness over the Mach number range between approximately 0.5 and 1.2 was obtained from the models and no indication of reversal of effectiveness was encountered. The ratio of tip helix angle to aileron deflection indicated a decrease in proportional rolling effectiveness with increasing deflections in the Mach number range from approximately 0.7 to 1.0. A drag rise of about 125 percent in the transonic region between Mach numbers of 0.85 and 1.02 followed by a gradual decrease at higher speeds was revealed.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL51D27
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  • 80
    Publication Date: 2019-07-11
    Description: An investigation has been made in the Langley gust tunnel with two identical airplane models approximating 1/40-scale models of the B-29, coupled in tandem with a boom so that the individual centers of gravity were equidistant from the single coupling joint at the tail of the lead airplane. Time histories of the boom joint load were obtained as the models were flown through a gust. The results indicate that on a similar configuration involving airplanes the size of B-29 airplanes a load on the boom joint of 10,000 to 14,000 pounds could be induced by encountering a gust of 50 feet per second and having a gradient distance of 17 chords, at a forward speed of 380 feet per second and that the total load is extremely sensitive to the steadiness of flight that can be maintained with or without a gust. It is felt that the results are probably satisfactory to show order of magnitude, but it does not appear possible that a precise determination of the joint load that would be applicable to the full-scale airplanes can be obtained by gust-tunnel tests.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL51E01A
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  • 81
    Publication Date: 2019-07-12
    Description: Free-flight tests have been made to determine the zero-lift drag of several configurations of the XAAM-N-2 pilotless aircraft. Base-pressure measurements were also obtained for some of the configurations. The results show that increasing the wing-thickness ratio from 4 to 6 percent increased the wing drag by about 100 percent at M = 1.3 and by about 30 percent at M = 1.8. Increasing the nose fineness ratio from 5.00 to 6.25 reduced the drag coefficient of the wingless models a maximum of about 0.030 (10 percent) at M = 2.0. A corresponding change in nose shape for the winged models decreased the drag coefficient by about 0.05 in the Mach number range from 1.1 to 1.4; at Mach numbers greater than 1.6 no measurable reduction in drag coefficient was obtained. The drag of the present Sparrow fuselage is less than that of a parabolic fuselage which could contain the same equipment.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SL50C16a
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  • 82
    Publication Date: 2019-07-12
    Description: An investigation was conducted with a single combustor from a J47 turbojet engine using weathered aviation gasoline and several spark-plug modifications to determine altitude ignition, acceleration, and steady state operating characteristics. Satisfactory ignition was obtained with two modifications of the original opposite-polarity spark plug up to and including an altitude of 40,003 feet at conditions simulating equilibrium windmilling of the engine at a flight speed of 400 miles per hour. At a simulated altitude of 30,000 feet, satisfactory ignition was obtained over a range of simulated engine speeds. No significant effect of fuel temperature on ignition limits was observed over a range of fuel temperatures from 80 deg to -52 deg F. At an altitude of 30,000 feet, the excess temperature rise available for acceleration at low engine speeds was limited by the ability of the combustor to produce temperature rise, whereas at high engine speeds the maximum allowable turbine-inlet temperature became the restricting factor. Altitude operational limits increased from about 51,500 feet at 55 percent of rated engine speed to about 64,500 feet at 85 percent of rated speed. Combustion efficiencies varied from 59.0 to 92.6 percent over the range investigated and decreased with a decrease in engine speed and with an increase in altitude; higher efficiencies would have been obtained if lower altitudes had been investigated. Comparisons were made of the combustion efficiencies of weathered aviation gasoline and MIL-F-5616 fuel at altitudes of 30,000 and 40,000 feet. Combustion efficiencies obtained with MIL-F-5616 fuel were 8 percent higher at rated engine speed and 14 percent lower at 55 percent of rated speed than those obtained with weathered aviation gasoline.
    Keywords: Aircraft Design, Testing and Performance
    Type: NACA-RM-SE50J12
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