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An Approximate Method for Calculation of the Laminar Boundary Layer with Suction for Bodies of Arbitrary Shape

Description: From Summary: "Various ways were tried recently to decrease the friction drag of a body in a flow; they all employ influencing the boundary layer. One of them consists in keeping the boundary layer Laminar by suction; promising tests have been carried out. Since for large Reynolds numbers the friction drag of the laminar boundary layer is much lower than that of the turbulent boundary layer, a considerable saving in drag results from keeping the boundary layer laminar, even with the blower powe… more
Date: March 1949
Creator: Schlichting, H.
Item Type: Refine your search to only Report
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Behavior of the Laminar Boundary Layer for Periodically Oscillating Pressure Variation

Description: "The calculation of the phenomena within the boundary layer of bodies immersed in a flow underwent a decisive development on the basis of L. Prandtl's trains of thought, stated more than forth years ago, and by numerous later treatises again and again touching upon them. The requirements of the steadily improving aerodynamics of airplanes have greatly increased with the passing of time and recently research became particularly interested in such phenomena in the boundary layer as are caused by … more
Date: September 1949
Creator: Quick, August Wilhelm & Schröder, K.
Item Type: Refine your search to only Report
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Boundary Layer Theory, Part 2, Turbulent Flows

Description: From Summary: "The flow laws of the actual flows at high Reynolds numbers differ considerably from those of the laminar flows treated in the preceding part. These actual flows show a special characteristic, denoted as turbulence. The character of a turbulent flow is most easily understood the case of the pipe flow. Consider the flow through a straight pipe of circular cross section and with a smooth wall. For laminar flow each fluid particle moves with uniform velocity along a rectilinear path." more
Date: April 1949
Creator: Schlichting, H.
Item Type: Refine your search to only Report
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Calculation of Counterrotating Propellers

Description: "A method for calculation of a counterrotating propeller which is similar to Walchner's method for calculation of the single propeller in the free air stream is developed and compared with measurements. Several dimensions which are important for the design are given end simple formulas for the gain in efficiency derived. Finally a survey of the behavior of the propeller for various operating conditions is presented" (p. 1).
Date: March 1949
Creator: Ginzel, F.
Item Type: Refine your search to only Report
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A Class of de Laval Nozzles

Description: "A study is made herein of the irrotational adiabatic motion of a gas in the transition from subsonic to supersonic velocities. A shape of the de Laval nozzle is given, which transforms a homogeneous plane-parallel flow at large subsonic velocity into a supersonic flow without any shockwaves beyond the transition line from the subsonic to the supersonic regions of flow. The method of solution is based on integration near the transition line of the gas equations of motion in the form investigate… more
Date: October 1949
Creator: Falkovich, S. V.
Item Type: Refine your search to only Report
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The Compressible Flow Past Various Plane Profiles Near Sonic Velocity

Description: "In an earlier report UM No.1117 by Gothert,the single-source method was applied to the compressible flow around circles, ellipses, lunes, and around an elongated body of revolution at different Mach numbers and the results compared as far as possible with the calculations by Lamla ad Busemann. Essentially, it was found that with favorable source arrangement the single-source method is in good agreement with the calculations of the same degree of approximation by Lamla and Busemann. Near sonic … more
Date: March 1949
Creator: Göthert, B. & Kawalki, K. H.
Item Type: Refine your search to only Report
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Compression Shocks in Two-Dimensional Gas Flows

Description: "The following are arguments on the compression shocks in gas flow start with a simplified representation of the results of the study made by Th. Meyer as published in the Forschungsheft 62 of the VDI, supplemented by several amplifications for the application. In the treatment of compression shocks, the equation of energy, the equation of continuity, the momentum equation, the equation of state of the particular gas, as well as the condition Of the second law of thermodynamics that no decrease… more
Date: February 1949
Creator: Busemann, A.
Item Type: Refine your search to only Report
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Computation of Thin-Walled Prismatic Shells

Description: "We consider a prismatic shell consisting of a finite number of narrow rectangular plates and having in the cross-section a finite number of closed contours (fig. 1(a)). We shall assume that the rectangular plates composing the shell are rigidly joined so that there is no motion of any kind of one plate relative to the others meeting at a given connecting line. The position of a point on the middle prismatic surface is considered to be defined by the coordinate z, the distance to a certain init… more
Date: June 1949
Creator: Vlasov, V. Z.
Item Type: Refine your search to only Report
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Effect of the Acceleration of Elongated Bodies of Revolution Upon the Resistance in a Compressible Flow

Description: The problem of the motion of an elongated body of revolution in an incompressible fluid may, as is known, be solved approximately with the aid of the distribution of sources along the axis of the body. In determining the velocity field, the question of whether the body moves uniformly or with an acceleration is no factor in the problem. The presence of acceleration must be taken into account in determining the pressures acting on the body. The resistance of the body arising from the accelerated… more
Date: May 1949
Creator: Frankl, F. I.
Item Type: Refine your search to only Report
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Exact Calculation of Laminar Boundary Layer in Longitudinal Flow Over a Flat Plate With Homogeneous Suction

Description: "Lately it has been proposed to reduce the friction drag of a body in a flow for the technically important large Reynolds numbers by the following expedient: the boundary layer, normally turbulent, is artificially kept laminar up to high Reynolds numbers by suction. The reduction in friction drag thus obtained is of the order of magnitude of 60 to 80 percent of the turbulent friction drag, since the latter, for large Reynolds numbers, is several times the laminar friction drag. In considering t… more
Date: April 1949
Creator: Iglisch, Rudolf
Item Type: Refine your search to only Report
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Experimental Flights for Testing of a Reactor as an Expedient for the Termination of Dangerous Spins

Description: "In the Institute for Flight Mechanics of the DVL a reactor arrangement with a maximum output of 100 kg was investigated as an expedient for the termination of dangerous spins on an airplane of the FW 56 type. reproduce the influence of a disturbance of the steady spin condition by a pitching or yawing moment. The tests were meant to reproduce the influence of a disturbance of the steady spin condition by a pitching and yawing moment" (p. 1).
Date: July 1949
Creator: Höhler, P. & v. Köppen, I.
Item Type: Refine your search to only Report
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Experimental study of flow past turbine blades

Description: From Introduction: "The requirements on gas turbines for aircraft power units, namely, adequate efficiency, operation at high gas temperatures, low weight, and small dimensions, must be taken into consideration during the design of the blading. To secure good efficiency, it is necessary that the gas flow past the blades as smoothly as possible without separation. This is relatively easily obtainable in the accelerated flow of turbine blading, if the blade spacing is chosen small enough. A small… more
Date: June 1949
Creator: Eckert, E. & Vietinghoff-Scheel, K. V.
Item Type: Refine your search to only Report
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Flow Measurement by Means of Light Interference

Description: "There has been under development for the high-speed wind tunnel of the LFA an optical measuring arrangement for the qualitative and quantitative investigation of flow. By the use of interference measurements, the determination of density at the surface of the bodies being tested in the air stream and in the vicinity of these bodies can be undertaken. The results obtained so far in the simple preliminary investigations show that it is possible, even at a low Reynolds number, to obtain the densi… more
Date: August 1949
Creator: Zobel
Item Type: Refine your search to only Report
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Flow Pattern in a Converging-Diverging Nozzle

Description: "The present report describes a new method for the prediction of the flow pattern of a gas in the two-dimensional and axially symmetrical case. It is assumed that the expansion of the gas is adiabatic and the flow stationary. The several assumptions necessary of the nozzle shape effect, in general, no essential limitation on the conventional nozzles" (p. 1).
Date: March 1949
Creator: Oswatitsch, K. & Rothstein, W.
Item Type: Refine your search to only Report
open access

Gas Motion in a Local Supersonic Region and Conditions of Potential-Flow Breakdown

Description: "For a certain Mach number of the oncoming flow, the local velocity first reaches the value of the local velocity of sound (M = 1) at some point on the surface of the body located within the flow. This Mach number is designated the critical Mach number M(sub cr). By increasing the flow velocity, a supersonic local region is formed bounded by the body contour and the line of transition from subsonic to supersonic velocity. As is shown by observations with the Toepler apparatus, at a certain flow… more
Date: May 1949
Creator: Nikolskii, A. A. & Taganov, G. I.
Item Type: Refine your search to only Report
open access

Heat Transmission in the Boundary Layer

Description: "In the present paper which deals with the heat transfer between the gas and the wall for large temperature drops and large velocities use is made of the method of Dorodnitsyn of the introduction of a new independent variable, with this difference, however, that the relation between the temperature field (that is, density) and the velocity field in the general case considered is not assumed given but is determined from the solution of the problem. The effect of the compressibility arising from … more
Date: April 1949
Creator: Kalikhman, L. E.
Item Type: Refine your search to only Report
open access

The Influence of the Application of Power during Spin Recovery of Multiengine Airplanes

Description: "The effect of application of power, so far not clarified, is investigated in the present report in order to give the pilot, in addition to the control measures, an expedient for spin recovery of multiengine airplanes. To this end, a series of spins was performed with an airplane of the Go 150 type. It was possible to set up a uniform rule regarding the effect of power, for right end left spins as well as for any combination of the direction of rotation of the propellers" (p. 1).
Date: June 1949
Creator: Höhler, P.
Item Type: Refine your search to only Report
open access

Investigation of Conditions of Titanium Carbonization - 4

Description: "In a previous paper, results are presented of accurate investigations of the processes of titanium carbonization and the succeeding titanium carbide decarbonization as related to the phenomenon of the graphitization of soot by heating at a constant temperature in atmospheres of pure hydrogen and carbon monoxide. These tests showed that the processes of titanium carbonization-decarbonization in an atmosphere of pure gases without nitrogen proceed in the same direction as the analogous processes… more
Date: July 1949
Creator: Meerson, G. A. & Lipkes, Y. M.
Item Type: Refine your search to only Report
open access

Investigations on the Stability, Oscillation, and Stress Conditions of Airplanes with Tab Control: First Partial Report. Derivation of the Equations of Motion and their General Solutions

Description: "For the design and the construction of airplanes the control is of special significance, not only with regard to the flight mechanical properties but also for the proportional arrangement of wing unit, fuselage, and tail unit. Whereas these problems may be regarded as solved for direct control of airplane motions, that is, for immediate operation of the control surfaces, they are not clarified as to oscillations, stability, and stress phenomena occurring in flight motions with Indirect control… more
Date: September 1949
Creator: Filzek, B.
Item Type: Refine your search to only Report
open access

Investigations on the Stability, Oscillation, and Stress Conditions of Airplanes With Tab Control: Second Partial Report: Application of the Solutions Obtained in the First Partial Report to Tab-Controlled Airplanes

Description: The first partial report, FB 2000, contained a discussion of the derivation of the equations of motion and their solutions for a tab-controlled airplane; the results obtained there are now to be applied to the longitudinal motion of tab-controlled airplanes. In view of the abundance of structural factors and aerodynamic parameters, a general discussion of the problems is unfeasible. Thus it is demonstrated on the basis of examples what stability, oscillation, and stress conditions are to be exp… more
Date: September 1949
Creator: Filzek, B.
Item Type: Refine your search to only Report
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