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  • Inorganic Chemistry  (123)
  • AIRCRAFT DESIGN, TESTING AND PERFORMANCE  (6)
  • 1
    Publication Date: 2011-08-24
    Keywords: AIRCRAFT DESIGN, TESTING AND PERFORMANCE
    Type: Journal of Aircraft (ISSN 0021-8669); 30; 5; p. 695-704.
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  • 2
    Publication Date: 2019-06-28
    Description: A computer simulation for 'running wet' and evaporative aircraft anti-icing systems is developed. The model is based on the analysis of the liquid water film which forms in the regions of direct impingement and, then, breaks up near the impingement limits into rivulets. The wetness factor distribution resulting from the film breakup and the rivulet configuration on the surface are predicted using a stability analysis theory and the laws of mass energy conservation. The solid structure is modeled as a multiple layer wall. The anti-icing system modeled is of the thermal type utilizing hot air and/or electrical heating elements embedded within the wall layers. Experimental observations revealing some of the basic physics of the water flow on the surface are presented. Detailed qualitative documentation of the tests are given. Several numerical examples are considered, and the effect of some of the involved parameters on the system performance are investigated.
    Keywords: AIRCRAFT DESIGN, TESTING AND PERFORMANCE
    Type: AIAA PAPER 92-0042
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  • 3
    Publication Date: 2019-06-28
    Description: In this paper, a finite element formulation based on an assumed states method is proposed for the solution of heat conduction problems with phase change at a fixed temperature. Attention is directed toward reduction of computer cost through the use of an efficient formulation, solver and algorithm. The procedure is applied to the analysis of an electrothermally deiced aircraft surface.
    Keywords: AIRCRAFT DESIGN, TESTING AND PERFORMANCE
    Type: AIAA PAPER 92-0532
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  • 4
    Publication Date: 2019-06-28
    Description: An overview of the deicing computer codes that have been developed at the University of Toledo under sponsorship of the NASA-Lewis Research Center is presented. These codes simulate the transient heat conduction and phase change occurring in an electrothermal deicier pad that has an arbitrary accreted ice shape on its surface. The codes are one-dimensional rectangular, two-dimensional rectangular, and two-dimensional with a coordinate transformation to model the true blade geometry. All modifications relating to the thermal physics of the deicing problem that have been incorporated into the codes will be discussed. Recent results of reformulating the codes using different numerical methods to increase program efficiency are described. In particular, this reformulation has enabled a more comprehensive two-dimensional code to run in much less CPU time than the original version. The code predictions are compared with experimental data obtained in the NASA-Lewis Icing Research Tunnel with a UH1H blade fitted with a B. F. Goodrich electrothermal deicer pad. Both continuous and cyclic heater firing cases are considered. The major objective in this comparison is to illustrate which codes give acceptable results in different regions of the airfoil for different heater firing sequences.
    Keywords: AIRCRAFT DESIGN, TESTING AND PERFORMANCE
    Type: AIAA PAPER 88-0288
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  • 5
    Publication Date: 2019-06-28
    Description: A hot air anti-icing system of a gas turbine engine inlet is analyzed numerically. A three-dimensional potential flow code, which accounts for compressibility effects, is used to determine the flowfield in and around the inlet. A particle trajectory code is developed using a local linearization technique. The trajectory code is used to calculate local water impingement rates. Energy balances are performed on both the surface runback water and the metallic skin to determine their temperature distributions. A variety of test cases are considered in order to validate the various numerical components of the process as well as to demonstrate the procedure.
    Keywords: AIRCRAFT DESIGN, TESTING AND PERFORMANCE
    Type: AIAA PAPER 89-0759
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  • 6
    Publication Date: 2019-07-12
    Keywords: AIRCRAFT DESIGN, TESTING AND PERFORMANCE
    Type: Journal of Aircraft (ISSN 0021-8669); 26; 554-562
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1522-1535 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Aromatic Erythrina-Alkaloids, XIV. Application of the Glyoxylester Synthesis to DihydroresorcinolThe monocycloketal 7 of dihydroresorcinol yields, via glyoxylester synthesis, the condensation product 10. On treatment with dilute phosphoric acid, 10 hydrolyses to give the partially hydrogenated ketoisatin derivative 14a which is stabilised by conjugation and cannot be cyclised. In the presence of crystalline phosphoric acid 10 forms a violet cation, Pictet-Spengler cyclisation of which leads to a mixture of stereoisomeric spiroisoquinolines (22). From the mixture two racemates are isolated, the n. m. r. analysis of which permits the assignment of cis- and trans-configurations according to the formulae 22A and 22B.
    Notes: Aus dem Monocycloketal 7 des Dihydroresorcins wird auf dem Weg der Glyoxylestersynthese die Cyclisierungsvorstufe 10 gewonnen. Sie hydrolysiert unter der Einwirkung von verdünnter phosphorsäure zu dem Partiell hydrierten Ketoisatin-Derivat 14a, das durch Konjugation stabilisiert und nicht cyclisierbar ist. Mit kristalliner Phosphorsäure entsteht aus 10 ein violettes Kation, das durch Ringschluß nach Pictet-Spengler zu einem Gemisch stereoisomerer Spiroisochinoline 22 abreagiert. Nach Auftrennung in zwei Racemate wird durch NMR-Analyse die sterische Zuordnung zur cis- und trans-Reihe entsprechend den Formulierungen 22A und 22B ermittelt.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 3800-3812 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bullvaleno-Crown Ethers with Variable Ring SizesSyntheses and properties of the bullvaleno-crown ethers 1a-e are described. An analysis of the temperature dependent 1H NMR spectra proves an easily occurring thermally induced change of ring size within certain limits. The relatively small association constants reveal a weak „guesthost„ interaction of 1a-e with alkali and ammonium rhodanide. The stoichiometry of the complexes and preferred positional isomers of the ligands of the complexes are reported for alkali and ammonium picrates. The possible adaption of the „breathing„ crown ethers to cations of different sizes is not observed.
    Notes: Es werden Synthesen und Eigenschaften der Bullvaleno-kronenether 1a-e beschrieben. Die Analyse der temperaturabhängigen 1H-NMR-Spektren beweist, daß sich die Ringgröße dieser Verbindungen thermisch leicht innerhalb bestimmter Grenzen verändert. Die relativ kleinen Assoziationskonstanten zeigen nur eine schwache „Gast-Wirt“-Wechselwirkung zwischen 1a-e und Alkali- und Ammoniumpikraten sowie tert-Butylammoniumrhodanid an. Die Stöchiometrie der Komplexe und bevorzugte Positionsisomere der Liganden in den Komplexen werden für Alkali- und Ammoniumpikrate angegeben. Die mögliche Adaption der „atmenden“ Kronenether an Kationen verschiedener Größe wird nicht beobachtet.
    Additional Material: 7 Tab.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1372-1379 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Six- and Eight-membered Sulfur-Nitrogen-Heterocycles - Compounds of Sulfur with the Formal Oxidation States 2, 4, and 6The reaction of the eight-membered compound S4N4O2 with silylamines having several substituents and tris(trimethylstannyl)amine yields the six- and eight-membered heterocycles 1-3. The six-membered rings 1 and, 2 are the first examples where the sulfur atoms have the formal oxidation states 2, 4, and 6. 1 and 2 can also be synthesized by the reaction of silyl- and stannyl-substituted sulfur diimide with N-sulfinylfluorosulfonamide. 2 and 3 are also obtained by the reaction of S4N4O2, with trimethyltin azide. The structure of 2 was determined by an X-ray analysis. 2 crystallizes in the space group P2l. Five of the six-ring atoms form a plane. The nitrogen atom coordinated to the tin lies 78 pm above this plane. The S — N bond lengths are discussed in connection with known structures.
    Notes: Die Umsetzung der Achtringverbindung S4N4O2 mit mehrfach substituierten Silylaminen und Tris(trimethylstannyl)amin führt zu den Sechs- bzw. Achtring-Heterocyclen 1-3. Die Sechsringe 1 und 2 sind die ersten Beispiele, in denen der Schwefel die formalen Oxidationsstufen 2, 4 und 6 erreicht. 1 und 2 lassen sich auch durch Umsetzung von N-Sulfinylfluorsulfonamid mit silyl- oder stannylsubstituiertem Schwefeldiimid darstellen. 2 und 3 sind ebenfalls zugänglich durch die Umsetzung von S4N4O2 mit Trimethylzinnazid. Die Struktur von 2 wurde durch eine Röntgen-analyse aufgeklärt. 2 kristallisiert in der Raumgruppe P21. Fünf der sechs Ringatome bilden eine Ebene, während das Stickstoffatom, welches am Zinnatom gebunden ist. um 78 pm außerhalb der Ringebene liegt. Die S — N-Bindungslängen werden im Zusammenhang mit bisher bekannten Strukturen diskutiert.
    Additional Material: 1 Ill.
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  • 10
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Salts of S4N4O2 - Examples for the Dependence of the Structure of Cyclic Sulfur-Nitrogen Compounds on the Electron DensityThe reaction of S4N4O2 with nucleophiles (alcoholates, alcohols, azides, and isocyanates) in alcoholic solution leads to the salts 1a-h. The Structure of 1h was determined by means of an X-ray analysis. 1h crystallizes in the space group P21/n and contains a transannular S—S-bond with 248.2 (2) pm. The structure of 1h is considered in connection with the increase of electron density and compared with the results of the X-ray analysis of CH3Si(NSN)3SiCH3 (2). 2 is cubic (space group P4132). The bicyclic molecule (S—N 150.4(2), Si—N 173.7 (2) pm) has approximate D3h symmetry and shows no S—S bonds across the rings.
    Notes: Die Umsetzung von S4N4O2 mit Nucleophilen (Alkoholate, Alkohole, Azide und Isocyanate) in alkoholischem Medium führt zu den Salzen 1a-h. Für 1h wurde eine Röntgenstrukturanalyse durchgeführt. 1h kristallisiert in der Raumgruppe P21/n und enthält eine transannulare S—S Bindung mit 248.2 (2) pm. Die Struktur von 1h wird im Zusammenhang mit der Zunahme der Elektronendichte betrachtet und mit den Ergebnissen der Röntgenstrukturanalyse von CH3Si(NSN)3SiCH3 (2) verglichen. 2 kristallisiert kubisch (Raumgruppe P4132). Das bicyclische Molekül (S—N 150.4 (2), Si—N 173.7 (2)pm) hat praktisch D3h Symmetrie und zeigt keine S—S-Bindungen im Ring.
    Additional Material: 2 Ill.
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