National Advisory Committee for Aeronautics (NACA) - 79 Matching Results

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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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fundamental Aerodynamic Investigations for Development of Arrow-Stabilized Projectiles

Description: "The numerous patent applications on arrow-stabilized projectiles indicate that the idea of projectiles without spin is not new, but has appeared in various proposals throughout the last decades. As far as projectiles for subsonic speeds are concerned, suitable shapes have been developed for sometime, for example, numerous grenades. Most of the patent applications, though, are not practicable particularly for projectiles with supersonic speed" (p. 1).
Date: December 1947
Creator: Kurzweg, Hermann
Item Type: Refine your search to only Report
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
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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On the Application of the Energy Method to Stability Problems

Description: "Since stability problems have come into the field of vision of engineers, energy methods have proved to be one of the most powerful aids in mastering them. For finding the especially interesting critical loads special procedures have evolved that depart somewhat from those customary in the usual elasticity theory. A clarification of the connections seemed desirable,especially with regard to the post-critical region, for the treatment of which these special methods are not suited as they are" (… more
Date: October 1947
Creator: Marguerre, Karl
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Ram-Jet Engine for Fighters

Description: Simple and accurate calculations are made of the flow process in a continuous compressorless Lorin jet-propulsion unit. Experimental confirmation is given from towing tests on an airplane at flying speeds up to 200 miles per second. An analysis is made of the performance of a fighter-type airplane designed for utilization of this propulsion system.
Date: October 1947
Creator: Sänger, E. & Bredt, I.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculations and Experimental Investigations on the Feed-Power Requirement of Airplanes With Boundary-Layer Control

Description: "Calculations and test results are given about the feed-power requirement of airplanes with boundary-layer control. Curves and formulas for the rough estimate of pressure-loss and feed-power requirement are set up for the investigated arrangements which differ structurally and aerodynamically. According to these results the feed power for three different designs is calculated at the end of the report" (p. 1).
Date: September 1947
Creator: Krüger, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Determination of the Stress Concentration Factor of a Stepped Shaft Stressed in Torsion by Means of Precision Strain Gages

Description: The stress distribution in stepped shafts stressed in torsion is determined by means of the electric precision strain gage the stress concentration factor is ascertained from the measurements. It is shown that the test values always are slightly lower than the values resulting from an approximate formula.
Date: September 1947
Creator: Weigand, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Development and Construction of an Interferometer for Optical Measurements of Density Fields

Description: "A method of interference is described in the present report which promises profitable application in aeronautical research. The physical foundation of the method and a simple method of adjustment are briefly discussed. The special technical construction of the instrument is described which guarantees its use also in the case of vibrations of the surrounding space and permits the investigation of unsteady phenomena" (p. 1).
Date: September 1947
Creator: Zobel
Item Type: Refine your search to only Report
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
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Russian Laminar Flow Airfoils 3rd Part: Measurements on the Profile No. 2315 BIS with Ava-Nose Flap

Description: "The tests on the Russian airfoil 2315 Bis were continued. This airfoil shows, according to Moscow tests, good laminar flow characteristics. Several tests were prepared in the large wind tunnel at Gottingen; partial results were obtained" (p. 1).
Date: September 1947
Creator: Riegels, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Temperatures and Stresses on Hollow Blades For Gas Turbines

Description: "The present treatise reports on theoretical investigations and test-stand measurements which were carried out in the BMW Flugmotoren GMbH in developing the hollow blade for exhaust gas turbines. As an introduction the temperature variation and the stress on a turbine blade for a gas temperature of 900 degrees and circumferential velocities of 600 meters per second are discussed. The assumptions on the heat transfer coefficients at the blade profile are supported by tests on an electrically hea… more
Date: September 1947
Creator: Pollmann, Erich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigations on a Changed Mustang Profile with Nose Flap Force and Pressure-Distribution Measurements

Description: "Measurements are described which were taken in the large wind tunnel of the AVA on a rectangular wing "Mustang 2" with nose flap of a chord of 10 percent. Besides force measurements the results of pressure-distribution measurements are given and compared with those on the same profile "without" nose flap" (p. 1).
Date: September 1947
Creator: Krüger, W.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Equations for Adiabatic but Rotational Steady Gas Flows Without Friction

Description: This paper makes the following assumptions: 1) The flowing gases are assumed to have uniform energy distribution. ("Isoenergetic gas flows," that is valid with the same constants for the the energy equation entire flow.) This is correct, for example, for gas flows issuing from a region of constant pressure, density, temperature, end velocity. This property is not destroyed by compression shocks because of the universal validity of the energy law.
Date: August 1947
Creator: Schäefer, Manfred
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigations on Reductions of Friction on Wings, in Particular by Means of Boundary Layer Suction

Description: Memorandum presenting investigation on reductions of friction on wings, especially by means of boundary-layer suction. The report is broken up into several sections, including: causes of transition, laminar profiles with the transition taking place, laminar boundary-layer suction, investigation of the laminar pressure increase, investigation of the slot flow for laminar boundary-layer suction with single slots, tests about keeping a boundary layer for high Reynolds laminar with the aid of bound… more
Date: August 1947
Creator: Pfenninger, Werner
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Lift and Drag of Wings with Small Span

Description: The lift coefficient of a wing of small span at first shows a linear increase for the increasing angle of attack, but to a lesser degree then was to be expected according to the theory of the lifting line; thereafter the lift coefficient increases more rapidly than linearity, as contrasted with the the theory of the lifting line. The induced drag coefficient for a given lift coefficient, on the other hand, is obviously much smaller than it would be according to the theory. A mall change in the … more
Date: August 1947
Creator: Weinig, F.
Item Type: Refine your search to only Report
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
Item Type: Refine your search to only Report
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
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Drag Corrections in High-Speed Wind Tunnels

Description: In the vicinity of a body in a wind tunnel the displacement effect of the wake, due to the finite dimensions of the stream, produces a pressure gradient which evokes a change of drag. In incompressible flow this change of drag is so small, in general, that one does not have to take it into account in wind-tunnel measurements; however, in compressible flow it beoomes considerably larger, so that a correction factor is necessary for measured values. Correction factors for a closed tunnel and an o… more
Date: July 1947
Creator: Ludwieg, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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