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Investigations of Compression Shocks and Boundary Layers in Gases Moving at High Speed

Description: The mutual influences of compression shocks and friction boundary layers were investigated by means of high speed wind tunnels.Schlieren optics provided a clear picture of the flow phenomena and were used for determining the location of the compression shocks, measurement of shock angles, and also for Mach angles. Pressure measurement and humidity measurements were also taken into consideration.Results along with a mathematical model are described.
Date: January 1947
Creator: Ackeret, J.; Feldmann, F. & Rott, N.
Partner: UNT Libraries Government Documents Department
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Calculation of the Pressure Distribution on Bodies of Revolution in the Subsonic Flow of a Gas Part 1 - Axially Symmetrical Flow

Description: "The present report concerns a method of computing the velocity and pressure distributions on bodies of revolution in axially symmetrical flow in the subsonic range. The differential equation for the velocity potential Phi of a compressible fluid motion is linearized tn the conventional manner, and then put in the form Delta(Phi) = 0 by affine transformation. The quantity Phi represents the velocity potential of a fictitious incompressible flow, for which a constant superposition of sources by … more
Date: July 1947
Creator: Bilharz, Herbert & Hölder, Ernst
Partner: UNT Libraries Government Documents Department
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The Monoplane as a Lifting Vortex Surface

Description: "In Prandtl's airfoil theory the monoplane was replaced by a single lifting vortex line and yielded fairly practical results. However, the theory remained restricted to the straight wing. Yawed wings and those curved in flight direction could not be computed with this first approximation; for these the chordwise lift distribution must be taken into consideration. For the two-dimensional problem the transition from the lifting line to the lifting surface has been explained by Birnbaum. In the pr… more
Date: February 1947
Creator: Blenk, Hermann
Partner: UNT Libraries Government Documents Department
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Infinitesimal Conical Supersonic Flow

Description: The calculation of infinitesimal conical supersonic flow has been applied first to the simplest examples that have also been calculated in another way. Except for the discovery of a miscalculation in an older report, there was found the expected conformity. The new method of calculation is limited more definitely to the conical case.
Date: March 1947
Creator: Busemann, Adolf
Partner: UNT Libraries Government Documents Department
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Rockets Using Liquid Oxygen

Description: "It is my task to discuss rocket propulsion using liquid oxygen and my treatment must be highly condensed for the ideas and experiments pertaining to this classic type of rocket are so numerous that one could occupy a whole morning with a detailed presentation. First, with regard to oxygen itself as compared with competing oxygen carriers, it is known that the liquid state of oxygen, in spite of the low boiling point, is more advantageous than the gaseous form of oxygen in pressure tanks, there… more
Date: April 1947
Creator: Busemann, Adolf
Partner: UNT Libraries Government Documents Department
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The Effect of Turbulence on the Flame Velocity in Gas Mixtures

Description: "The present report deals with the effect of turbulence on the propagation of the flame. Being based upon experiments with laminar as well as turbulent Bunsen flames, both the physico-chemical and the hydro-dynamical aspects of the problem are analyzed. A number of new deductions, interesting from the point of view of engine combustion and other very rapidly changing flame reactions, are made" (p. 1).
Date: April 1947
Creator: Damköhler, Gerhard
Partner: UNT Libraries Government Documents Department
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Description of Russian Aircraft Engines "AM 35" and "AM 38"

Description: The Russian AM 35 and AM 38 aircraft engines have superchargers with a swirl throttle, which appears to be a purely Russian development. This paper gives the results of test runs of the two engines, including the effects of the swirl throttle on engine performance.
Date: June 1947
Creator: Denkmeier, H. & Gross, K.
Partner: UNT Libraries Government Documents Department
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Possibilities of Reducing the Length of Axial Superchargers for Aircraft Motors

Description: Axial blowers are gaining importance as aircraft engine superchargers. However, the pressure head obtainable per stage is small. Due to the necessary great number of stages, the physical length of the blower becomes too great for an airworthy device. This report discusses several types of construction that permit a reduction in the length of the blower.
Date: January 1947
Creator: Eckert, B.
Partner: UNT Libraries Government Documents Department
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Recent Results on High-Pressure Axial Blowers

Description: "Considerable progress has, in recent times, been attained in the development of the high-pressure axial blower by well-planned research. The efforts are directed toward improving the efficiencies, which are already high for the axial blower, and in particular the delivery pressure heads. For high pressures multistage arrangements are used. Of fundamental importance is the careful design of all structural parts of the blower that are subject to the effects of the flow. In the present report, se… more
Date: April 1947
Creator: Eckert, B.
Partner: UNT Libraries Government Documents Department
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Compression Shocks of Detached Flow

Description: "It is known that compression shocks which lead from supersonic to subsonic velocity cause the flow to separate on impact on a rigid wall. Such shocks appear at bodies with circular symmetry or wing profiles on locally exceeding sonic velocity, and in Laval nozzles with too high a back pressure. The form of the compression shocks observed therein is investigated" (p. 1).
Date: June 1947
Creator: Eggink
Partner: UNT Libraries Government Documents Department
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Investigations on Experimental Impellers for Axial Blowers

Description: "A selection of measurements obtained on experimental impellers for axial blowers will be reported. In addition to characteristic curves plotted for low and for high peripheral velocities, proportions and blade sections for six different blower models and remarks on the design of blowers will be presented" (p. 1).
Date: April 1947
Creator: Encke, W.
Partner: UNT Libraries Government Documents Department
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Concerning the Velocity of Evaporation of Small Droplets in a Gas Atmosphere

Description: "The evaporation velocity of liquid droplets under various conditions is theoretically calculated and a number of factors are investigated which are neglected in carrying out the fundamental equation of Maxwell. It is shown that the effect of these factors at the small drop sizes and the small weight concentrations ordinarily occurring in fog can be calculated by simple corrections. The evaporation process can be regarded as quasi-stationary in most cases" (p. 1).
Date: August 1947
Creator: Fuchs, N.
Partner: UNT Libraries Government Documents Department
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Investigation of the Operating Properties of the Leakage Current Anemometer

Description: "Freedom from inertia, erosion of electrodes, and reaction make the leakage current particularly appropriate for the measurement of flow velocities in gases. Apparatus previously described has now been improved by reducing the size of the electrodes by one -thousandth, as is necessary aerodynamically, and by increasing the magnitude of the current from 1000 to 10,000 times; the latter result was obtained.by use of mercury high-pressure lamps set up at the one focal point of an ellipsoidal refle… more
Date: October 1947
Creator: Fucks, Wilhelm
Partner: UNT Libraries Government Documents Department
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The Turbulent Flow in Diffusers of Small Divergence Angle

Description: "The turbulent flow in a conical diffuser represents the type of turbulent boundary layer with positive longitudinal pressure gradient. In contrast to the boundary layer problem, however, it is not necessary that the pressure distribution along the limits of the boundary layer(along the axis of the diffuser) be given, since this distribution can be obtained from the computation. This circumstance, together with the greater simplicity of the problem as a whole, provides a useful basis for the st… more
Date: October 1947
Creator: Gourzhienko, G. A.
Partner: UNT Libraries Government Documents Department
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High-Speed Measurements on a Swept-Back Wing (Sweepback Angle phi = 35 Deg)

Description: "In the following, high-speed measurements on a swept-back wing are reported. The curves of lift, moment, and drag have been determined up to Mach numbers of M = 0.87, and they are compared to a rectangular wing. Through measurements of the total-head loss behind the wing and through schlieren pictures, an insight into the formation of the compression shock at high Mach numbers has been obtained" (p. 1).
Date: March 1947
Creator: Göthert, B.
Partner: UNT Libraries Government Documents Department
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Cones in Supersonic Flow

Description: "In the case of cones in axially symmetric flow of supersonic velocity, adiabatic compression takes place between shock wave and surface of the cone. Interpolation curves betwen shock polars and the surface are therefore necessary for the complete understanding of this type of flow. They are given in the present report by graphical-numerical integration of the differential equation for all cone angles and airspeeds" (p. 1).
Date: August 1947
Creator: Hantzsche, W. & Wendt, H.
Partner: UNT Libraries Government Documents Department
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Pressure Distribution Measurements on a Turbine Rotor Blade Passing Behind a Turbine Nozzle Lattice

Description: "As a turbine rotor turns, the blades traverse the wake zones of the nozzle vanes. A periodic fluctuation of the pressure distribution around the circumference of the rotor blade is therefore caused. It was desired to investigate quantitatively this effect. At the same time, the magnitude of the force acting upon one profile of the rotor-blade lattice at various positions of this lattice relative to the nozzle lattice was to be determined" (p. 1).
Date: September 1947
Creator: Hausenblas
Partner: UNT Libraries Government Documents Department
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Analytical Treatment of Normal Condensation Shock

Description: "The condensation of water vapor in an air has the following consequences: acquisition of heat (liberated heat vaporization; loss of mass on the part of the flowing gas (water vapor is converted to liquid); change in the specific gas constants and of the ratio k of the specific heats (caused by change of gas composition). A discontinuous change of state is therefore connected with the condensation; schlieren photographs of supersonic flows in two-dimensional Laval nozzles show two intersecting … more
Date: July 1947
Creator: Heybey
Partner: UNT Libraries Government Documents Department
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Three-Component Force and Mass-Flow Measurement on a Jet Nacelle

Description: The present report contains three-component forces and mass-flow measurements on a jet nacelle at small inlet-velocity ratios v(sub A)/v(sub o) < 1. The mass-flow measurement on two cross sections of the nacelle demonstrate the local-velocity distribution with varying flow and angle of attack.
Date: June 1947
Creator: Ilgmann, G. & Möller, E.
Partner: UNT Libraries Government Documents Department
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The Elasto-Plastic Stability of Plates

Description: This article explains results developed from the following research: 'The Stability of Plates and Shells beyond the Elastic Limit.' A significant improvement is found in the derivation of the relations between the stress factors and the strains resulting from the instability of plates and shells. In a strict analysis, the problem reduces to the solution of two simultaneous nonlinear partial differential equations of the fourth order in the deflection and stress function, and in the approximate … more
Date: December 1947
Creator: Ilyushin, A. A.
Partner: UNT Libraries Government Documents Department
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Stability of Plates and Shells Beyond the Proportional Limit

Description: In the present paper is examined the method of investigating the stability of plates and shells beyond the elastic limit, that proceeds from the generalization of the Hencky-Mises theory of elastico-plastic deformations given in the works of Smirnov-Alyayev, Schmidt, and in our papers.
Date: October 1947
Creator: Ilyushin, A. A.
Partner: UNT Libraries Government Documents Department
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