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A New Simple Interferometer for Obtaining Quantitatively Evaluable Flow Patterns

Description: "The method described in the present report makes it possible to obtain interferometer records with the aid of any one of the available Schlieren optics by the addition of very simple expedients, which fundamentally need not to be inferior to those obtained by other methods, such as the Mach-Zehnder interferometer, for example. The method is based on the fundamental concept of the phase-contrast process developed by Zernike, but which in principle has been enlarged to such an extent that it pra… more
Date: November 1953
Creator: Erdmann, S. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Concerning the Flow About Ring-Shaped Cowlings 12: Two New Classes of Circular Cowls

Description: "For application in practice for annular radiator fairings and similar arrangements, two new classes of circular cowls are developed by theoretical method, and investigated in a systematic test series regarding their behavior under various working conditions" (p. 1).
Date: October 1953
Creator: Küchemann, Dietrich & Weber, Johanna
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Air-Water Analogy and the Study of Hydraulic Models

Description: From Summary: "The author first sets forth some observations about the theory of models. Then he established certain general criteria for the construction of dynamically similar models in water and in air, through reference to the perfect fluid equations and to the ones pertaining to viscous flow. It is, in addition, pointed out that there are more cases in which the analogy is possible than is commonly supposed."
Date: July 1953
Creator: Supino, Giulio
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Air Admixture to Exhaust Jets

Description: From Introduction: "The problem of thrust increase for jet engines by air mixture to the exhaust jet was introduced into aviation techniques by the suggestions of Melot (ref.1). Due to a too general interpretation of several theoretical investigations of A. Busemann (ref.2), so far no practical use has been made of these suggestions. The following considerations show that, in the case of low-pressure mixing according to Melot's suggestions, probably no thrust increase of technical significance … more
Date: July 1953
Creator: Sänger, Eugen
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Study of the Supersonic Propeller

Description: In this paper a propeller having all sections operating at supersonic speeds is designated a supersonic propeller regardless of flight speed. Analyses assume subsonic flight speeds but very high rotational speeds. A very elementary analysis of the efficiency of a jet-propeller system is presented. A propeller analysis based on conventional vortex blade element theory is presented and reduced to a single point method which leads to an expression for optimum advance ratio in terms of hub-tip diam… more
Date: March 1953
Creator: Fabri, Jean & Siestrunck, Raymond
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Some Problems on the Theory of Creep

Description: "The term creep of metals is applied to the phenomenon in which, at temperatures beyond a certain limit, the metal subjected to a load slowly undergoes deformation with time. Very slow deformations for a prolonged period are cumulative and lead either to inadmissible changes in the dimensions of a structural part or to its failure. The theory of creep constitutes part of the mechanics of dense media and the mechanical formulation of the problem may be given as the following: a body is subjected… more
Date: April 1953
Creator: Rabotnov, Y. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Microstructure of Turbulent Flow

Description: "In 1941 a general theory of locally isotropic turbulence was proposed by Kolmogoroff which permitted the prediction of a number of laws of turbulent flow for large Reynolds numbers. The most important of these laws, the dependence of the mean square of the difference in velocities at two points on their distance and the dependence of the coefficient of turbulence diffusion on the scale of the phenomenon, were obtained by both Kolmogoroff and Obukhoff in the same year. At the present time these… more
Date: June 1953
Creator: Obukhoff, A. M. & Yaglom, A. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

On the Theory of the Turbulent Boundary Layer

Description: As a rule, a division of the turbulent boundary layer is admissible: a division into a part near the wall, where the flow is governed only by the wall effects, and into an outer part, where the wall roughness and the viscosity of the flow medium affects only the wall shearing stress occurring as boundary condition but does not exert any other influence on the flow. Both parts may be investigated to a large extent independently. . The theoretical considerations give a cue how to set up, by appro… more
Date: February 1953
Creator: Rotta, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Steady Vibrations of Wing of Circular Plan Form and Theory of Wing of Circular Plan Form

Description: This paper treats the problem of determining the lift, moment, and induced drag of a thin wing of circular plan form in uniform incompressible flow on the basis of linearized theory. As contrasted to a similar paper by Kinner, in which the acceleration potential method was used, the present paper utilizes the concept of the velocity potential. Calculations of the lift and moment are presented for several deformed shapes.
Date: January 1953
Creator: Kochin, N. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Supersaturation in the Spontaneous Formation of Nuclei in Water Vapor

Description: "According to experience, a certain supersaturation is required for condensation of water vapor in the homogeneous phase; that is, for inception of the condensation, at a prescribed temperature, the water vapor partial pressure must lie above the saturation pressure. The condensation starts on so-called condensation nuclei. Solid or liquid suspended particles may serve as nuclei; these particles may either a priori be present in the gas phase (dust, soot), or may spontaneously be formed from th… more
Date: November 1953
Creator: Sander, Adolf & Damköhler, Gerhard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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