Technical Report Archive & Image Library (TRAIL) - 17 Matching Results

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The Coupling of Flexural Propeller Vibrations with the Torsional Crankshaft Vibrations

Description: The exact mathematical treatment of the problem is possible by replacing the propeller blade by a homogeneous prismatic rod. Conclusions can them be drawn as to the behavior of an actual propeller, since tests on propeller blades have indicated a qualitative agreement with the homogeneous rod. The natural frequencies are determined and the stressing of the systems under the various vibration modes are discussed.
Date: December 1943
Creator: Meyer, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Determination of the Mass Moments and Radii of Inertia of the Sections of a Tapered Wing and the Center-of-Gravity Line Along the Wing Span

Description: "For computing the critical flutter velocity of a wing among the data required are the position of the line of centers of gravity of the wing sections along the span and the mass moments and radii of inertia of any section of the wing about the axis passing through the center of gravity of the section. A sufficiently detailed computation of these magnitudes even if the weights of all the wing elements are known, requires a great deal of time expenditure. Thus a rapid competent worker would requ… more
Date: December 1943
Creator: Savelyev, V. V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental Investigation of a Model of a Two-Stage Turboblower

Description: "In the present paper an investigation is made of two stages of a multistage turboblower having a vaneless diffuser behind the impeller and guide vanes at the inlet to the nest stage. The method employed was that of investigating the performance of the successive elements of the blower (the impeller, vaneless diffuser, ets.) whereby the kinematics of the flow through the blower could be followed and the pressure at the different points computed. The character of the flow and the physical signif… more
Date: April 1943
Creator: Dovjik, S. & Polikovsky, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental Investigation of Impact in Landing on Water

Description: "The extent of agreement of the theoretical impact computations with the actual phenomenon has not as yet been fully clarified. There is on the one hand a certain imperfection in the theory (simplifying assumptions made) and on the other an insufficiency in the experimental data available. The object of our present paper is to show how far test results agree with the available approximate computation methods, to investigate in greater detail the physical nature of impact on water, and to perfec… more
Date: August 1943
Creator: Kreps, R. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Heat Transfer and Hydraulic Flow Resistance for Streams of High Velocity

Description: "Problems of hydraulic flow resistance and heat transfer for streams with velocities comparable with acoustic have present great importance for various fields of technical science. Especially, they have great importance for the field of heat transfer in designing and constructing boilers.of the "Velox" type. In this article a description of experiments and their results as regards definition of the laws of heat transfer in differential form for high velocity air streams inside smooth tubes are … more
Date: December 1943
Creator: Lelchuk, V. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Heat Transfer of Airfoils and Plates

Description: "The few available test data on the heat dissipation of wholly or partly heated airfoil models are compared with the corresponding data for the flat plate as obtained by an extension of Prandtl's momentum theory, with differentiation between laminar and turbulent boundary layer and transitional region between both, the extent and appearance of which depend upon certain critical factors. The satisfactory agreement obtained justifies far-reaching conclusions in respect to other profile forms and … more
Date: April 1943
Creator: Seibert, Otto
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Heat Transfer Over the Circumference of a Heated Cylinder in Transverse Flow

Description: "A method for recording the local heat-transfer coefficients on bodies in flow was developed. The cylinder surface was kept at constant temperature by the condensation of vapor except for a narrow strip which is heated separately to the same temperature by electricity. The heat-transfer coefficient at each point was determined from the electric heat output and the temperature increase" (p. 1).
Date: October 1943
Creator: Schmidt, Ernst & Wenner, Karl
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Heat Transfer Through Turbulent Friction Layers

Description: "The "general Prandtl number" Pr(exp 1) - A(sub q)/A Pr, aside from the Reynolds number determines the ratio of turbulent to molecular heat transfer, and the temperature distribution in turbulent friction layers. A(sub q) = exchange coefficient for heat; A = exchange coefficient for momentum transfer. A formula is derived from the equation defining the general Prandtl number which describes the temperature as a function of the velocity" (p. 1).
Date: September 1943
Creator: Reichardt, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Heat Transfer to a Plate in Flow at High Speed

Description: From Summary: "The heat transfer in the laminar boundary layer of a heated plate in flow at high speed can be obtained by integration of the conventional differential equations of the boundary layer, so long as the material values can be regarded as constant. This premise is fairly well satisfied at speeds up to about twice the sonic speed and at not excessive temperature rise of the heated plate. The general solution of the equation includes Pohlhausen's specific cases of heat transfer to a pl… more
Date: May 1943
Creator: Eckert, E. & Drewitz, O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Periodic Heat Transfer at Small Pressure Fluctuations

Description: "The effect of cyclic gas pressure variations on the periodic heat transfer at a flat wall is theoretically analyzed and the differential equation describing the process and its solution for relatively. Small pressure fluctuations developed, thus explaining the periodic heat cycle between gas and wall surface. The processes for pure harmonic pressure and temperature oscillations, respectively, in the gas space are described by means of a constant heat transfer coefficient and the equally consta… more
Date: September 1943
Creator: Pfriem, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Piezoelectric Instruments of High Natural Frequency Vibration Characteristics and Protection Against Interference by Mass Forces

Description: "The exploration of the processes accompanying engine combustion demands quick-responding pressure-recording instruments, among which the piezoelectric type has found widespread use because of its especially propitious properties as vibration-recording instruments for high frequencies. Lacking appropriate test methods, the potential errors of piezoelectric recorders in dynamic measurements could only be estimated up to now. In the present report a test method is described by means of which the … more
Date: February 1943
Creator: Gohlke, Werner
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Piston Ring Pressure Distribution

Description: "The discovery and introduction of the internal combustion engine has resulted in a very rapid development in machines utilizing the action of a piston. Design has been limited by the internal components of the engine, which has been subjected to ever increasing thermal and mechanical stresses. Of these internal engine components, the piston and piston rings are of particular importance and the momentary position of engine development is not seldom dependent upon the development of both of the … more
Date: December 1943
Creator: Kuhn, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Pressure Distribution in Nonuniform Two-Dimensional Flow

Description: In an attempt to follow the time rate of change of the processes in turbulent flows by quantitative measurements the measurement of the pressure is often beset with insuperable difficulties for the reason that the speeds and hence the pressures to be measured are often very small. On the other hand, the measurement of very small pressures requires, at least, considerable time, so that the follow-up of periodically varying processes is as goad as impossible. In order to obviate these difficultie… more
Date: January 1943
Creator: Schwabe, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Researches on Preliminary Chemical Reactions in Spark-Ignition Engines

Description: "Chemical reactions can demonstrably occur in a fuel-air mixture compressed in the working cylinder of an Otto-cycle (spark ignition) internal-combustion engine even before the charge is ignited by the flame proceeding from the sparking plug. These are the so-called "prelinminary reactions" ("pre-flame" combustion or oxidation), and an exact knowledge of their characteristic development is of great importance for a correct appreciation of the phenomena of engine-knock (detonation), and conseque… more
Date: June 1943
Creator: Mühlner, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tail Buffeting

Description: "An approximate theory of buffeting is here presented, based on the assumption of harmonic disturbing forces. Two cases of buffeting are considered: namely, for a tail angle of attack greater and less than the stalling angle, respectively. On the basis of the tests conducted and the results of foreign investigators, a general analysis is given of the nature of the forced vibrations the possible load limits on the tail, and the methods of elimination of buffeting" (p. 1).
Date: February 1943
Creator: Abdrashitov, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Theoretical Determination of Axial Fan Performance

Description: "The report presents a method for the computation of axial fan characteristics. The method is based on the assumption that the law of constancy of the circulation along the blade holds, approximately, for all fan conditions for which the blade elements operate at normal angles of attack (up to the stalling angles). Pressure head coefficient K(sub a) and power coefficient K(sub u) for the force components in the axial and tangential directions, respectively, and analogous to the lift and drag co… more
Date: April 1943
Creator: Struve, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Turbulent Friction in the Boundary Layer of a Flat Plate in a Two-Dimensional Compressible Flow at High Speeds

Description: "In the present report an investigation is made on a flat plate in a two-dimensional compressible flow of the effect of compressibility and heating on the turbulent frictional drag coefficient in the boundary layer of an airfoil or wing radiator. The analysis is based on the Prandtl-Karman theory of the turbulent boundary later and the Stodola-Crocco, theorem on the linear relation between the total energy of the flow and its velocity. Formulas are obtained for the velocity distribution and the… more
Date: December 1943
Creator: Frankl, F. & Voishel, V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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