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State and Development of Flutter Calculation

Description: This report discusses the need for considering a wide variation in certain of the basic flutter parameters in conducting a flutter analysis. Conclusions are drawn stating that design charts or simple rules may be misleading. Due to inherent difficulties, dynamic model testing may also yield misleading results. The general flutter equations and various methods of solution are discussed. Of particular interest, curves are presented showing computational effort plotted against a number of degrees … more
Date: March 1951
Creator: Teichmann, Alfred
Partner: UNT Libraries Government Documents Department
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On the Theory of Combustion of Initially Unmixed Gases

Description: The chemical reaction of two substances (fuel and oxygen) accompanied by the formation of new substances of the products of combustion and the liberation of heat is considered. General equations are provided as well as an analysis of the equation and the distribution of products of the reaction.
Date: June 1951
Creator: Zeldovich, Y. B.
Partner: UNT Libraries Government Documents Department
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Exhaust Turbine and Jet Propulsion Systems

Description: DVL experimental and analytical work on the cooling of turbine blades by using ram air as the working fluid over a sector or sectors of the turbine annulus area is summarized. The subsonic performance of ram-jet, turbo-jet, and turbine-propeller engines with both constant pressure and pulsating-flow combustion is investigated. Comparison is made with the performance of a reciprocating engine and the advantages of the gas turbine and jet-propulsion engines are analyzed. Nacelle installation meth… more
Date: April 1951
Creator: Leist, Karl & Knörnschild, Eugen
Partner: UNT Libraries Government Documents Department
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On Stability and Turbulence of Fluid Flows

Description: This investigation is divided into two parts, the treatment of the stability problem of fluid flows on the one hand, and that of the turbulent motion on the other. The first part summarizes all previous investigations under a unified point of view, that is, sets up as generally as possible the conditions under which a profile possesses unstable or stable characteristics, and indicates the methods for solution of the stability equation for any arbitrary velocity profile and for calculation of th… more
Date: June 1951
Creator: Heisenberg, Werner
Partner: UNT Libraries Government Documents Department
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The Structure of Airy's Stress Function in Multiply Connected Regions

Description: In solving two-dimensional problems using Airy's stress function for multiply connected regions, the form of the function depends on the dislocations and boundary forces present. The structure of Airy's function is shown to consist of a part expressible in terms of boundary forces and a part expressible in the manner of Poincare. Meanings of the constants occurring in Poincare's expression are discussed.
Date: July 1951
Creator: Grioli, Giusippe
Partner: UNT Libraries Government Documents Department
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Method of Successive Approximations for the Solution of Certain Problems in Aerodynamics

Description: A method of successive approximations for the solution of problems in the fields of diffusion, boundary-layer flow, and heat-transfer is illustrated by solving problems in each of these fields. In most of the examples, the approximate solutions are compared with known accurate solutions and the agreement is shown to be good.
Date: April 1951
Creator: Shvets, M. E.
Partner: UNT Libraries Government Documents Department
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Sideslip in a Viscous Compressible Gas

Description: By an analysis of the Navier-Stokes equations it is shown that the aerodynamic coefficients of an infinite rectangular swept wing in an isothermal or adiabatic flow of a compressible gas can be determined from the aerodynamic coefficients of the unswept wing. When the flow is neither isothermal nor adiabatic, a three-dimensional boundary layer theory is developed and applied to the special case of a swept flat plate.
Date: April 1951
Creator: Struminsky, V. V.
Partner: UNT Libraries Government Documents Department
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Behavior of Fast Moving Flow of Compressible Gas in Cylindrical Pipe in Presence of Cooling

Description: For compressible flow with friction in a cylindrical pipe the momentum, continuity, and heat-transfer equations are examined to determine whether an increase in Mach number ("thermal" Laval nozzle) is obtainable through heat conduction from the gas through the pipe walls. The analysis is based on the assumption that the wall temperature is negligibly small in comparison with the stagnation temperature of the gas. The analysis leads to a negative result. When the gas cooling is increased by also… more
Date: September 1951
Creator: Varshavsky, G. A.
Partner: UNT Libraries Government Documents Department
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Resonance Sound Absorber With Yielding Wall

Description: A single-sheet resonance system for normal incidence of sound was investigated to study in detail the effect of sympathetic vibration of the resonator front wall on sound absorption.
Date: May 1951
Creator: Rzhevkin, S. N.
Partner: UNT Libraries Government Documents Department
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Critical Velocities of Ultracentrifuges

Description: The Euler equations for the rotation of a solid body are applied to the problem of the motion of ultracentrifuges. Particular attention is paid to the problem of the passage of an ultracentrifuge rotor through the critical velocity. The factors that affect the passage of rotors through the critical point are stressed.
Date: March 1951
Creator: Sokolov, V. I.
Partner: UNT Libraries Government Documents Department
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Resistance of a delta wing in a supersonic flow

Description: The resistance of a delta wing at small angle of attack in supersonic conical flow with its leading edges within the Mach cone is calculated by a method that separates out the suction force.
Date: April 1951
Creator: Karpovich, E. A. & Frankl, F. I.
Partner: UNT Libraries Government Documents Department
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Theory of Flame Propagation

Description: "The mechanism of flame propagation has been qualitatively formulated. In accordance with this formulation, the chemical reaction initiated in some layer brings about an increase in the temperature; because of the heat conduction, the temperature is raised in the neighboring layer where in turn the chemical reaction is initiated. In this manner the flame is propagated" (p. 1).
Date: June 1951
Creator: Zeldovich, Y. B.
Partner: UNT Libraries Government Documents Department
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Unstable Capillary Waves on Surface of Separation of Two Viscous Fluids

Description: "The study of the breakup of a liquid jet moving in another medium, for example, a jet of fuel from a nozzle, shows that for sufficiently large outflow velocities the jet breaks up into a certain number of drops of different diameters. At still larger outflow velocities, the continuous part of the jet practically vanishes and the jet immediately breaks up at the nozzle into a large number of droplets of varying diameters (the case of "atomization"). The breakup mechanism in this case has a very… more
Date: April 1951
Creator: Borodin, V. A. & Dityakin, Y. F.
Partner: UNT Libraries Government Documents Department
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Correction Factors for Wind Tunnels of Elliptic Section With Partly Open and Partly Closed Test Section

Description: Jet boundary corrections for partly open and partly closed elliptical wind tunnels for the cases of one and two solid wall segments are presented. Also presented are the combinations of model span and extent of the solid portion of the tunnel wall for which the average correction factor is zero.
Date: March 1951
Creator: Riegels, Fritz W.
Partner: UNT Libraries Government Documents Department
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On the Theory of Thin and Thin-Walled Rods

Description: Through the work of V. Z. Vlasov a theory of thin-walled rods has been established that is widely applicable in practice. This theory was extended by A. A. Umanski to thin-walled rods of closed profile section. This report attempts to construct a theory of thin-walled rods, including the classical theory of deformation of thin rods, by making use of a kinematic assumption.
Date: October 1951
Creator: Dzhanelidze, G. Y.
Partner: UNT Libraries Government Documents Department
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On Motion of Fluid in Boundary Layer Near Line of Intersection of Two Planes

Description: From Summary: "In the paper "The Mutual Interference of Boundary Layers," the authors investigated the problem of the interference of two planes intersecting at right angles on the boundary layers formed by the motion of fluid along the line of intersection of these planes. In the present paper, the results of the preceding one are generalized to the case of planes intersecting at any angle. The motion of a fluid in an angle less than 180 degrees is discussed and the enlargement of the boundary… more
Date: November 1951
Creator: Loitsianskii, L. G. & Bolshakov, V. P.
Partner: UNT Libraries Government Documents Department
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Lateral Control by Spoilers at the DVL

Description: "The present report describes the development of spoiler control at the DVL from the end of 1936 until the beginning of 1939. The authors are fully aware that the present report also forms only a contribution to the problem of spoiler control and offers at best a possibility of extrapolation regarding the behavior of the control in modern airplanes. A modern airplane (Me 109) is being reconstructed for conversion to spoiler control" (p. 1).
Date: August 1951
Creator: Kramer, Max; Zobel, Theodor W. & Esche, C. G.
Partner: UNT Libraries Government Documents Department
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Three Papers From Conference On "Wing and Tail-Surface Oscillations: March 6-8, 1941, Munich

Description: Memorandum presenting three papers regarding aerodynamic balance of control surfaces. The specific topics covered include some general remarks regarding aerodynamically balanced control surfaces, aerodynamically equivalent systems for various forms of control surfaces within the scope of two-dimensional wing theory, and comparative calculations concerning aerodynamic balance of control surfaces.
Date: August 1951
Creator: Söhngen, Heinz; Schwarz, L. & Dietze, F.
Partner: UNT Libraries Government Documents Department
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On Ionization and Luminescence in Flames

Description: An explanation based upon reaction kinetics is presented to account for the deviation of measured ionization levels obtained from reflection experiments from the values computed assuming chemical equilibrium. The heat transfer to the unburned fuel is also considered.
Date: April 1951
Creator: Sänger, E.; Goercke, P. & Bredt, I.
Partner: UNT Libraries Government Documents Department
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Generalization of Joukowski formula to an airfoil of a cascade in compressible gas stream with subsonic velocities

Description: It is shown that the ordinary Joukowski formula for lift force of cascade blades in incompressible flow can be applied to the case of subsonic compressible flow with sufficient accuracy, provided that the density in the formula is taken as the arithmetic mean of the densities far ahead of and behind the cascade.
Date: September 1951
Creator: Loitsianskii, L. G.
Partner: UNT Libraries Government Documents Department
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Resistance of cascade of airfoils in gas stream at subsonic velocity

Description: A method of computing the resistance of a cascade of airfoils in a viscous compressible gas flow is described. The investigation occurred in subsonic velocities only because of the required assumption of isentropic flow.
Date: September 1951
Creator: Loitsianskii, L. G.
Partner: UNT Libraries Government Documents Department
open access

Stability of the Cylindrical Shell of Variable Curvature

Description: "This report is a first attempt to devise a calculation method for representing the buckling behavior of cylindrical shells of variable curvature. The problem occurs, for instance, in dimensioning wing noses, the stability of which is decisively influenced by the variability of curvature. The calculation is made possible by simplifying the stability equations (permissible for the shell of small curvature) and by assuming that the curvature 1/R as a function of the arc lengths can be represented… more
Date: July 1951
Creator: Marguerre, Karl
Partner: UNT Libraries Government Documents Department
open access

The Flow of Gases in Narrow Channels

Description: Measurements were made of the flow of gases through various narrow channels a few microns wide at average pressures from 0.00003 to 40 cm. Hg. The flow rate, defined as the product of pressure and volume rate of flow at unit pressure difference, first decreased linearly with decrease in mean pressure in the channel, in agreement with laminar-flow theory, reached a minimum when the mean path length was approximately equal to the channel width, and then increased to a constant value. The product … more
Date: August 1951
Creator: Rasmussen, R. E. H.
Partner: UNT Libraries Government Documents Department
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