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  • Other Sources  (27)
  • Aerodynamics  (23)
  • Seismology  (4)
  • Industrial Chemistry
  • Inorganic Chemistry
  • Mice
  • 2010-2014
  • 1950-1954
  • 1940-1944  (27)
  • 1942  (21)
  • 1940  (6)
Collection
Source
Keywords
Publisher
Years
  • 2010-2014
  • 1950-1954
  • 1940-1944  (27)
Year
  • 1
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    Earthquake magnitude, intensity, energy, and acceleration (1942)
    In:  Bull. Seism. Soc. Am., Milano, Gustav Fischer, vol. 32, no. 6, pp. 163-192, pp. L24306, (ISBN: 0534351875, 2nd edition)
    Details
    Publication Date: 1942
    Keywords: Seismology ; Magnitude ; Energy (of earthquakes) ; Intensity ; Strong motions ; BSSA ; FROTH ; (abstract)
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    BIBLIOGRAPHY SEISMOLOGY
  • 2
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    Earthquakes and structure in Southern California (1942)
    In:  Bull. Geol. Soc. Am., Milano, Gustav Fischer, vol. 53, no. 6, pp. 1818-1819, pp. L24306, (ISBN: 0534351875, 2nd edition)
    Details
    Publication Date: 1942
    Keywords: Seismology ; Earth model, also for more shallow analyses ! ; CRUST
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    BIBLIOGRAPHY SEISMOLOGY
  • 3
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    Preliminary Results of Flight Tests of a Conventional Three-Blade Propeller at High Speeds (1942)
    In:  CASI
    Details
    Publication Date: 2018-06-05
    Description: As part of the program of flight tests of airplane propellers to determine compressibility effects at high speeds, preliminary flights have been made with a conventional three-blade propeller (Hamilton Standard 3155-6) on a Bell YP-39 airplane. This preliminary report presents the high-speed data obtained thus far with a brief analysis of the results.
    Keywords: Aerodynamics
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  • 4
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    High-speed Tests of a Ducted Body with Various Air-outlet Openings (1942)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Test of a ducted body with Internal flow were made in the 8-foot high-speed wind tunnel for the purpose of studying the effects on external drag and an critical speed of the addition of efficient inlet and outlet openings to a basic streamline shape. Drag tests of a 13.6- inch-diameter streamline body of fineness ratio 6.14 were made at Mach numbers ranging from 0.20 to 0.75. The model was centrally mounted on a 9-percent-thick airfoil and was designed to have an efficient airfoil-body juncture and a high critical speed. An air inlet at the nose and various outlets at the tail were added: drag and internal-flow data were obtained over the given speed range. The critical speed of the ducted bodies was found to be as high as that of the streamline body. The external - drag with air flow through the body did not exceed the drag of the basic streamline shape. No appreciable variation in the efficiency of the diffuser section of the internal duct occurred throughout the Mach number range of the tests.
    Keywords: Aerodynamics
    Type: NACA-WR-L-486
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  • 5
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    The Longitudinal Stability of Flying Boats as Determined by Tests of Models in the NACA Tank II : Effect of Variations in Form of Hull on Longitudinal Stability (1942)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Data taken from tests at constant speed to establish trim limits of stability, tests at accelerated speeds to determine stable limits of center of gravity shift, and tests at decelerated speeds to obtain landing characteristics of several model hull forms were used to establish hull design effect on longitudinal stability of porpoising. Results show a reduction of dead rise angle as being the only investigated factor reducing low trim limit. Various methods of reducing afterbody interference increased upper trim limit
    Keywords: Aerodynamics
    Type: NACA-WR-L-468
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  • 6
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    The Characteristics of Two Model Six-blade Counterrotating Pusher Propellers of Conventional and Improved Aerodynamic Design (1942)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Two airfoil plans were used for propeller blades. One is modified Clark Y section designed for structural reliability and the second an NACA 16 airfoil section designed to produce minimum aerodynamic losses. At low air speeds, the propeller designed for aerodynamic effects showed a gain of from 1.5 to 4.0 percent in propulsive efficiency over the conventional type depending on the pitch. Because of the numerous variables involved, the effect of each one on the aerodynamic characteristics of the propellers could not be isolated.
    Keywords: Aerodynamics
    Type: NACA-WR-L-404
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  • 7
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    The Porpoising Characteristics of a Planing Surface Representing the Forebody of a Flying-Boat Hull (1942)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Porpoising characteristics were observed on V-body fitted with tail surfaces for different combinations of load, speed, moment of inertia, location of pivot, elevator setting, and tail area. A critical trim was found which was unaltered by elevator setting or tail area. Critical trim was lowered by moving pivot either forward or down or increasing radius or gyration. Increase in mass and moment of inertia increased amplitude of oscillations. Complete results are tabulated and shown graphically.
    Keywords: Aerodynamics
    Type: NACA-WR-L-479
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  • 8
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    An Investigation of Hydrofoils in the NACA Tank I : Effect of Dihedral and Depth of Submersion (1942)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Tests were conducted on hydrofoil assemblies approximating an arrangement for use under seaplanes or surface boats. A series of hydrofoils, each supported by two struts, was towed at various depths ranging from partial submersions to a depth of 5-chord lengths. At depths greater than 4 or 5 chords, the influence of the surface of the water is small; hydrofoils operating at low speed will have characteristics similar to those of airfoils of the same section.
    Keywords: Aerodynamics
    Type: NACA-WR-L-758
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  • 9
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    Application of Balancing Tabs to Ailerons (1942)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Analysis was made to determine characteristics required of a balancing-tab system for ailerons in order to reduce aileron stick forces to any desired magnitude. Series of calculations based on section data were made to determine balancing-tab systems of various chord tabs and ailerons that will give, for a particular airplane, zero rate of aileron hinge moment with aileron deflection and yet will produce same maximum rate of roll as a plain unbalanced 15-percent chord aileron of same span. Effects of rolling velocity and of forces in tab link on aileron hinge moments have been included.
    Keywords: Aerodynamics
    Type: NACA-WR-L-346
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  • 10
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    Flight Tests of Modifications to Improve the Aileron Control Characteristics of a North American XP-51 Airplane (AC No. 41-38) (1942)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Investigations were undertaken to improve the ailerons of a P-51 fighter so as to obtain greater effectiveness without increasing the stick forces. Modifications consisted of increasing the deflection range of the aileron to 70 percent and changing the original concave section to a thick section with beveled trailing edge. Results of the modified ailerons showed an increase in effectiveness over the original aileron of 70 percent at low speed and 55 percent at high speeds.
    Keywords: Aerodynamics
    Type: NACA-WR-L-636
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  • 11
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    Investigation of a Low-Drag Gun Port in the NACA Two-Dimensional Low-Turbulence Tunnel (1942)
    In:  CASI
    Details
    Publication Date: 2018-06-05
    Description: Tests were made in the NACA two-dimensional low-turbulence tunnel of three gun ports with a height of approximately 4 percent of the chord faired into an NACA 66,2-213 low-drag-airfoil section by bulging the section at the gun port. Gun ports faired in this manner had practically no effect on the maximum lift and the critical compressibility speed of the section and showed only small increase in the drag in the range of lift coefficients for high-speed and cruising-flight conditions.
    Keywords: Aerodynamics
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  • 12
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    Investigation of Extreme Leading-Edge Roughness on Thick Low-Drag Airfoils to Indicate Those Critical to Separation (1942)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Several airfoils, Including a conventional NACA 23021 and some low-drag airfoils for which the thickness had been increased to the point that they were considered doubtfully conservative with respect to separation, were investigated as smooth airfoils and after the application of a standard roughness. The results show some of the airfoils to be critical to separation resulting from such flow disturbances. It is concluded, pending the further investigation of separation difficulties, that airfoil sections falling definitely within the conservative range should be used.
    Keywords: Aerodynamics
    Type: NACA-WR-L-659
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  • 13
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    Two-Dimensional Potential Flow Past an Ordinary Thick Wing Profile (1942)
    In:  CASI
    Details
    Publication Date: 2019-08-17
    Description: This report deals with the development of a method which gives a lucid and convenient solution of the flow conditions in the vicinity of a common, thick airfoil section wherein the thickness of the profile is taken into account. The method consists in making the airfoil the streamline in a parallel flow by disposing on its mean line certain source and vortex distributions the fields of which are superposed on the parallel flow. These distributions of singularities are secured for the generalized Karman-Trefftz profile by means of conformal transformation from the flow about a circle. Five different distribution functions are afforded for the density of superposition, which combine in a specified manner to the necessary distributions of singularity and represent a generalized Karman-Trefftz profile in parallel flow. For these profiles the speed for each of the five distributions is then computed independently of the angle of attack.
    Keywords: Aerodynamics
    Type: NACA-TM-1023
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  • 14
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    Pressure-Distribution Measurements of a Model of a Davis Wing Section with Fowler Flap Submitted by Consolidated Aircraft Corporation (1942)
    In:  CASI
    Details
    Publication Date: 2019-08-14
    Description: Wing pressure distribution diagrams for several angles of attack and flap deflections of 0 degrees, 20 degrees, and 40 degrees are presented. The normal force coefficients agree with lift coefficients obtained in previous test of the same model, except for the maximum lifts with flap deflection. Pressure distribution measurements were made at Reynolds Number of about 6,000,000.
    Keywords: Aerodynamics
    Type: NACA-WR-L-678
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  • 15
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    Aerodynamic Characteristics for Internal-Balance and Frise Type Ailerons on an NACA 6 Series Low-Drag Tip Section of the Wing for the XP-63 Airplane (1942)
    In:  CASI
    Details
    Publication Date: 2019-08-07
    Description: At the request of the Army Air Forces, Materiel Command, tests were made in the two-Dimensional low-turbulence tunnel of a mode l submitted by Bell Aircraft Corporation as the tip section of the wing of the xp-63 airplane. " The model was a NACA 66, 2x-2l6 a = 0.6 airfoil section of 50-inch chord and made of dural according to standard sheet-metal practice. The model was fitted for an internal-balance aileron with a tab and a Frise type aileron. Several alterations of the skirts and balance on the internal- balance aileron were tested to obtain the various aerodynamic characteristics of the aileron.
    Keywords: Aerodynamics
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  • 16
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    Aerodynamics of the Fuselage (1942)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The present report deals with a number of problems, particularly with the interaction of the fuselage with the wing and tail, on the basis of simple calculating method's derived from greatly idealized concepts. For the fuselage alone it affords, in variance with potential theory, a certain frictional lift in yawed flow, which, similar to the lift of a wing of small aspect ratio, is no longer linearly related to the angle of attack. Nevertheless there exists for this frictional lift something like a neutral stability point the position of which on oblong fuselages appears to be associated with the lift increase of the fuselage in proximity to the zero lift, according to the present experiments. The Pitching moments of the fuselage can be determined with comparatively great reliability so far as the flow conditions in the neighborhood of the axis of the fuselage can be approximated if the fuselage were absent, which, in general, is not very difficult. For the unstable contribution of the fuselage to the static longitudinal stability of the airplane it affords comparatively simple formulas, the evaluation of which offers little difficulty. On the engine nacelles there is, in addition a very substantial wing moment contribution induced by the nonuniform distribution of the transverse displacement flow of the nacelle along the wing chord; this also can be represented by a simple formula. A check on a large number of dissimilar aircraft types regarding the unstable fuselage and nacelle moments disclosed an agreement with the wind-tunnel tests, which should be sufficient for practical requirements. The errors remained throughout within the scope of instrumental accuracy.
    Keywords: Aerodynamics
    Type: NACA-TM-1036 , Luftfahrtforschung; 18; 3-Feb; 52-56
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  • 17
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    Tests of an NACA 66,2-420 Airfoil of 5-Foot Chord at High Speed, Special Report (1942)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: This report covers tests of a 5-foot model of the NACA 66,2-420 low-drag airfoil at high speeds including the critical compressibility speed. Section coefficients of lift, drag, and pitching moment, and extensive pressure-distribution data are presented. The section drag coefficient at the design lift coefficient of 0.4 increased from 0.0042 at low speeds to 0.0052 at a Mach number of 0.56 (390 mph at 25,000 ft altitude). The critical Mach number was about 0.60. The results cover a Reynold number range from 4 millions to 17 millions.
    Keywords: Aerodynamics
    Type: NACA-ACR-234 , NACA-SR-234
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    NASA TECHNICAL REPORTS
  • 18
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    Preliminary Wind-Tunnel Tests of the Effect of Nacelles on the Characteristics of a Twin-Engine Bomber Model with Low-Drag Wing, Special Report (1942)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: Tests were made in the NACA 19-foot pressure tunnel of a simplified twin-engine bomber model with an NACA low-drag wing primarily to obtain an indication of the effects of engine nacelles on the characteristics of the model both with and without simple split trailing-edge flaps. Nacelles with conventional-type cowlings representative of those used on an existing high-performance airplane and with NACA high-speed type E cowlings were tested. The tests were made without propeller slipstream. The aerodynamic effects of adding the nacelles to the low-drag wing were similar to the effects commonly obtained by adding similar nacelles to conventional wings. The maximum lift coefficient without flaps was slightly increased, but the increment in maximum lift due to deflecting the flaps was somewhat decreased. The stalling characteristics were improved by the presence of the nacelles. Addition of the nacelles had a destabilizing effect on the pitching moments, as is usual for nacelles that project forward of the wing. The drag increments due to the nacelles were of the usual order of magnitude, with the increment due to the nacelles with NACA type E cowlings approximately one-third less than that of the nacelles with conventional cowlings with built-in air scoops.
    Keywords: Aerodynamics
    Type: NACA-ACR-225 , NACA-SR-225
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  • 19
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    Wind-Tunnel Development of Ailerons for the Curtiss XP-60 Airplanem Special Report (1942)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: An investigation was made in the LWAL 7- by 10-foot tunnel of internally balanced, sealed ailerons for the Curtiss XP-60 airplane. Ailerons with tabs and. with various amounts of balance were tested. Stick forces were estimated for several aileron arrangements including an arrangement recommended for the airplane. Flight tests of the recommended arrangement are discussed briefly in an appendix, The results of the wind-tunnel and flight tests indicate that the ailerons of large or fast airplanes may be satisfactorily balanced by the method developed.
    Keywords: Aerodynamics
    Type: NACA-ACR-257 , NACA-SR-257
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  • 20
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    A Brief Study of the Speed Reduction of Overtaking Airplanes by Means of Air Brakes, Special Report (1942)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: As an aid to airplane designers interested in providing pursuit airplanes with decelerating devices intended to increase the firing time when overtaking another airplane, formulas are given relating the pertinent distances and speeds in horizontal flight to the drag increase required. Charts are given for a representative parasite-drag coefficient from which the drag increase, the time gained, and the closing distance may be found. The charts are made up for three values of the ratio of the final speed of the pursuing airplane to the speed of the pursued airplane and for several values of the ratio of the speed of the pursued airplane to the initial speed of the pursuing airplane. Charts are also given indicating the drag increases obtainable with double split flaps and with conventional propellers. The use of the charts is illustrated by an example in which it is indicated that either double split flaps or, under certain ideal conditions, reversible propellers should provide the speed reductions required.
    Keywords: Aerodynamics
    Type: NACA-ACR-220 , NACA-SR-220
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  • 21
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    Tests If a Highly Cambered Low-Drag-Airfoil Section with a Lift-Control Flap, Special Report (1942)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: Tests were made in the NACA two-dimensional low turbulence pressure tunnel of a highly cambered low-drag airfoil (NACA 65,3-618) with a plain flap designed for lift control. The results indicate that such a combination offers attractive possibilities for obtaining low profile-drag coefficients over a wide range of lift coefficients without large reductions of critical speed.
    Keywords: Aerodynamics
    Type: NACA-ACR-242 , NACA-SR-242
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  • 22
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    Seismological Tables (1940)
    British Association for the Advancement of Science, Gray Milne Trust
    In:  London, 50 pp., 4th print., 1970, British Association for the Advancement of Science, Gray Milne Trust, vol. 46, no. XVI:, pp. 1-14, (ISBN: 0-387-30752-4)
    Details
    Publication Date: 1940
    Keywords: Earth model, also for more shallow analyses ! ; Travel time ; Seismology ; Handbook of geophysics
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    BIBLIOGRAPHY SEISMOLOGY
  • 23
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    Deep focus earthquakes in America (1940)
    University of California Press
    In:  Pacific Science Association, 6th Congress Proceedings, vol. 1, Toronto, University of California Press, vol. 10, no. GL-TR-89-0230, pp. 149-150, (ISBN 3-933346-037)
    Details
    Publication Date: 1940
    Keywords: Seismology ; Seismicity ; Hypocentral depth
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    BIBLIOGRAPHY SEISMOLOGY
  • 24
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    Wind-tunnel Tests of the NACA 45-125 Airfoil: A Thick Airfoil for High-Speed Airplanes (1940)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: Investigations of the pressure distribution, the profile drag, and the location of transition for a 30-inch-chord 25-percent-thick N.A,C.A. 45-125 airfoil were made in the N.A.C.A 8-foot high-speed wind tunnel for the purpose of aiding in the development of a thick wing for high-speed airplanes. The tests were made at a lift coefficient of 0.1 for Reynolds Numbers from 1,750,000 to 8,690,000, corresponding to speeds from 80 to 440 miles per hour at 59 F. The effect on the profile drag of fixing the transition point was also investigated. The effect of compressibility on the rate of increase of pressure coefficients was found to be greater than that predicted by a simplified theoretical expression for thin wings. The results indicated that, for a lift coefficient of 0.1, the critical speed of the N.A.C,A. 45-125 airfoil was about 460 miles per hour at 59 F,. The value of the profile-drag coefficient at a Reynolds Number of 4,500,000 was 0.0058, or about half as large as the value for the N.A,C,A. 0025 airfoil. The increase in the profile-drag coefficient for a given movement of the transition point was about three times as large as the corresponding increase for the N.A.C,A. 0012 airfoil. Transition determinations indicated that, for Reynolds Numbers up to ?,000,000, laminar boundary 1ayers were maintained over approximately 40 percent of the upper and the lower surfaces of the airfoil.
    Keywords: Aerodynamics
    Type: NACA-SR-138
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  • 25
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    Wind-Tunnel Investigation of the Lift Characteristics of an NACA 27-212 Airfoil Equipped with Two Types of Flap, Special Report (1940)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: An investigation has been made in the NACA 7- by 10-foot wind tunnel of a large chord NACA 27-212 airfoil with a 20% chord split flap and with two arrangements of a 25.66% chord slotted flap to determine the section lift characteristics as affected by flap deflection for the split flap and as affected by flap deflection, flap position, and slot shape for the slotted flap. For the two arrangements of the slotted flap, the flap positions for maximum section lift are given. Comparable data on the NACA 23012 airfoil equipped with similar flaps are also given. On the basis of maximum section lift coefficient, the slotted flap with an easy slot entry was slightly better than either the split flap or the slotted flap with a sharp slot entry. With both types of flap the decrease in the angle of attack, for maximum section lift coefficient, with flap deflection is large for the NACA 27-212 airfoil as compared with the NACA 23012 airfoil. Also with both flaps, the maximum section lift coefficient obtained with flaps is much lower for the NACA 27-212 airfoil than for the NACA 23012 airfoil.
    Keywords: Aerodynamics
    Type: NACA-SR-159
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  • 26
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    Full-Scale Tests of Several Propellers Equipped with Spinners, Cuffs, Airfoil and Round Shanks, and NACA 16-Series Sections, Special Report (1940)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: Wind-tunnel tests of several propeller, cuff, and spinner combinations were conducted in the 20 foot propeller-research tunnel. Three propellers, which ranged in diameter from 8.4 to 11.25 feet, were tested at the front end of a streamline body incorporating spinners of two diameters. The tests covered a blade angle range from 20 deg to 65 deg. The effect of spinner diameter and propeller cuffs on the characteristics of one propeller was determined. Test were also conducted using a propeller which incorporated aerodynamically good shank sections and using one which incorporated the NACA 16 series sections for the outer 20 percent of the blades. Compressibility effects were not measured, owing to the low testing speeds. The results indicated that a conventional propeller was slightly more efficient when tested in conjunction with a 28 inch diameter spinner than with a 23 inch spinner, and that cuffs increased the efficiency as well as the power absorption characteristics. A propeller having good aerodynamic shanks was found to be definitely superior from the efficiency standpoint to a conventional round-shank propeller with or without cuffs; this propeller would probably be considered structurally impracticable, however. The propeller incorporating the NACA 16 series sections at the tims were found to have a slightly higher efficiency than a conventional propeller; the take-off characteristics appeared to be equally good. The effects noted above probably would be accentuated at helical speeds at which compressibility effects would enter.
    Keywords: Aerodynamics
    Type: NACA-SR-168
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  • 27
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    Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel, Special Report (1940)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: Determinations of boundary-layer transition on the NACA 0012 and 2301 airfoils were made in the 8-foot high-speed wind tunnel over a range of Reynolds Numbers from 1,600,000 to 16,800,000. The results are of particular significance as compared with flight tests and tests in wind tunnels of appreciable turbulence because of the extremely low turbulence in the high-speed tunnel. A comparison of the results obtained on NACA 0012 airfoils of 2-foot and 5-foot chord at the same Reynolds Number permitted an evaluation of the effect of compressibility on transition. The local skin friction along the surface of the NACA 0012 airfoil was measured at a Reynolds Number of 10,000,000. For all the lift coefficient at which tests were made, transition occurred in the region of estimated laminar separation at the low Reynolds Numbers and approach the point of minimum static pressure as a forward limit at the high Reynolds Numbers. The effect of compressibility on transition was slight. None of the usual parameters describing the local conditions in the boundary layer near the transition point served as an index for locating the transition point. As a consequence of the lower turbulence in the 8-foot high-speed tunnel, the transition points occurred consistently farther back along the chord than those measured in the NACA full-scale tunnel. An empirical relation for estimating the location of the transition point for conventional airfoils on the basis of static-pressure distribution and Reynolds Number is presented.
    Keywords: Aerodynamics
    Type: NACA-SR-137
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