UNT Libraries Government Documents Department - 38 Matching Results

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Aerodynamic Heat-Power Engine Operating on a Closed Cycle

Description: "Hot-air engines with dynamic compressors and turbines offer new prospects of success through utilization of units of high efficiencies and through the employment of modern materials of great strength at high temperature. Particular consideration is given to an aerodynamic prime mover operating on a closed circuit and heated externally. Increase of the pressure level of the circulating air permits a great increase of limit load of the unit. This also affords a possibility of regulation for whic… more
Date: November 1942
Creator: Ackeret, J. & Keller, D. C.
Item Type: Refine your search to only Report
open access

Aerodynamics of the Fuselage

Description: "The present report deals with a number of problems, particularly with the interaction of the fuselage with the wing and tail, on the basis of simple calculating method's derived from greatly idealized concepts. For the fuselage alone it affords, in variance with potential theory, a certain frictional lift in yawed flow, which, similar to the lift of a wing of small aspect ratio, is no longer linearly related to the angle of attack. Nevertheless there exists for this frictional lift something l… more
Date: December 1942
Creator: Multhopp, H.
Item Type: Refine your search to only Report
open access

Analytical Theory of the Campini Propulsion System

Description: "The present report deals exclusively with the particular jet-propulsion system mentioned in the cited reports. The discussion is limited, for the present, to the analytical study of the efficiency and the consumption for the case of application to aircraft and to the plotting of the practical operating curves secured theoretically by the use of suitable experimental factors" (p. 1).
Date: March 1942
Creator: Campini, S.
Item Type: Refine your search to only Report
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The Compressible Potential Flow Past Elliptic Symmetrical Cylinders at Zero Angle of Attack and with No Circulation

Description: "For the tunnel corrections of compressible flows those profiles are of interest for which at least the second approximation of the Janzen-Rayleigh method can be applied in closed form. One such case is presented by certain elliptical symmetrical cylinders located in the center of a tunnel with fixed walls and whose maximum velocity, incompressible, is twice the velocity of flow. In the numerical solution the maximum velocity at the profile and the tunnel wall as well as the entry of sonic velo… more
Date: October 1942
Creator: Hantzsche, W. & Wendt, H.
Item Type: Refine your search to only Report
open access

Contribution to the Design of Plywood Shells

Description: "The writer sets out to prove by calculation and experiment that by extensive utilization of the skin to carry axial load (reduction of stringer spacing) the stringer sections can be made small enough to afford a substantial saving in structural weight. This saving ranges from 5 to about 40 percent" (p. 1).
Date: October 1942
Creator: Blumrich, S.
Item Type: Refine your search to only Report
open access

Contribution to the ideal efficiency of screw propellers

Description: From Summary: "The stipulation of best thrust distribution is applied to the annular elements of the screw propeller with infinitely many blades in frictionless, incompressible flow and an ideal jet propulsion system derived possessing hyperbolic angular velocity distribution along the blade radius and combining the advantage of uniform thrust distribution over the section with minimum slipstream and rotation losses. This system is then compared with a propeller possessing the same angular velo… more
Date: January 1942
Creator: Hoff, Wilhelm
Item Type: Refine your search to only Report
open access

Control of Torsional Vibrations by Pendulum Masses

Description: "Various versions of pendulum masses have been developed abroad within the past few years by means of which resonant vibrations of rotating shafts can be eliminated at a given tuning. They are already successfully employed on radial engines in the form of pendulous counterweights. Compared with the commonly known torsional vibration dampers, the pendulum masses have the advantage of being structurally very simple, requiring no internal damping and being capable of completely eliminating certain… more
Date: November 1942
Creator: Stieglitz, Albert
Item Type: Refine your search to only Report
open access

Correlation of Data on the Statistical Theory of Turbulence

Description: The statistical theory of turbulence affords an excellent medium for representing the kinematic conditions in turbulent flow and also serves as a valuable aid to exact experimental research. But it is still not developed enough for solving dynamic processes. Even in the simplest case of isotropic turbulence the calculation of the correlation curve or of the decrement of turbulence invariably reaches a point where clear-cut assumptions, such as omission of the inertia terms, or, earlier, mixing … more
Date: March 1942
Creator: Wieghardt, K.
Item Type: Refine your search to only Report
open access

The Design of Propeller Blade Roots

Description: Predicated on the assumption of certain normal conditions for engine and propeller, simple expressions for the static and dynamic stresses of propeller blade roots are evolved. They, in combination with the fatigue strength diagram of the employed material, afford for each engine power one certain operating point by which the state of stress serving as a basis for the design of the root is defined. Different stress cases must be analyzed, depending on the vibration tendency of engine and use of… more
Date: January 1942
Creator: Cordes, G.
Item Type: Refine your search to only Report
open access

Diagrams for Calculation of Airfoil Lattices

Description: "The field for curved blades is represented by a vortex series with a vortex removed at the blade point. Further, an example of calculation of a curved blade from this series is given, whereby the necessary accuracy required of the different methods in practice is shown according to the case considered" (p. 1).
Date: July 1942
Creator: Betz, Albert
Item Type: Refine your search to only Report
open access

Electrical Equipment for the Experimental Study of the Dynamics of Fluids

Description: "This report contains the description of electric anemometers and their application to the study of turbulent fluid flows, of electric tanks for the realization of the analogies between electrology and aerodynamics and their application to the study of varied technical problems, and lastly of the electric condenser type dynamometer and its application to the prediction of the aerodynamic forces on wing and airplane models in wind-tunnel tests and in controlled and spontaneous rotations" (p. 1).
Date: March 1942
Creator: Ferrari, Carlo
Item Type: Refine your search to only Report
open access

The Formation of Ice on Aircraft

Description: "The phenomenon accompanying the formation of ice on aircraft has been frequently discussed. The consequences of ice formation have been briefly analyzed in an article , but a definite physical solution of the problem has not been reached up to the present. Most of the authors agree that subcooled water droplets play a prominent part, but they fail to specify the exact manner in which this occurs" (p. 1).
Date: August 1942
Creator: Bleeker, W.
Item Type: Refine your search to only Report
open access

Heat Transfer in the Turbulent Boundary Layer of a Compressible Gas at High Speeds

Description: "The Reynolds law of heat transfer from a wall to a turbulent stream is extended to the case of flow of a compressible gas at high speeds. The analysis is based on the modern theory of the turbulent boundary layer with laminar sublayer. The investigation is carried out for the case of a plate situated in a parallel stream. The results are obtained independently of the velocity distribution in the turbulent boundar layer" (p. 1).
Date: October 1942
Creator: Frankl, F. & Voishel, V.
Item Type: Refine your search to only Report
open access

The Icing of Aircraft

Description: This technical memorandum presents a theoretical study of the processes accompanying the formation of ice on solid bodies. It discusses vapor pressure and sublimation in two air masses separated by a boundary area.
Date: September 1942
Creator: Robitzsch, M.
Item Type: Refine your search to only Report
open access

Investigation of Lubricants Under Boundary Friction

Description: Numerous observations of such lubrication processes within range of boundary friction on journal bearings and gear tooth profiles have strengthened the supposition that it should be possible to study the attendant phenomena with engineering methods and equipment. These considerations formed the basis of the present studies, which have led to the discovery of relations governing the suitability of bearing surfaces and the concept of "lubricating quality.".
Date: May 1942
Creator: Heidebroek, E. & Pietsch, E.
Item Type: Refine your search to only Report
open access

The Navier-Stokes Stress Principle for Viscous Fluids

Description: "The Navier-Stokes stress principle is checked in the light of Maxwell's mechanism of friction and in connection herewith the possibility of another theorem is indicated. The Navier-Stokes stress principle is in general predicated upon the conception of the plastic body. Hence the process is a purely phenomenological one, which Newton himself followed with his special theorem for one-dimensional flows" (p. 1).
Date: September 1942
Creator: Mohr, Ernst
Item Type: Refine your search to only Report
open access

New method of extrapolation of the resistance of a model planing boat to full size

Description: "The previously employed method of extrapolating the total resistance to full size with lambda(exp 3) (model scale) and thereby foregoing a separate appraisal of the frictional resistance, was permissible for large models and floats of normal size. But faced with the ever increasing size of aircraft a reexamination of the problem of extrapolation to full size is called for. A method is described by means of which, on the basis of an analysis of tests on planing surfaces, the variation of the we… more
Date: March 1942
Creator: Sottorf, W.
Item Type: Refine your search to only Report
open access

On the Symmetrical Potential Flow of Compressible Fluid Past a Circular Cylinder in the Tunnel in the Subcritical Zone

Description: "The two-dimensional symmetrical potential flow of compressible fluid past a circular cylinder placed in the center line of a straight tunnel is analyzed in second approximation according to the Jansen-Rayleigh method. The departure of the profile from the exact circular shape can be kept to the same magnitude as for the incompressible flow. The velocities in the narrowest section of the tunnel wall and at the profile edge are discussed in detail" (p. 1).
Date: June 1942
Creator: Lamla, Ernst
Item Type: Refine your search to only Report
open access

The Performance of a Vaneless Diffuser Fan

Description: "The present paper is devoted to the theoretical and experimental investigation of one of the stationary elements of a fan, namely, the vaneless diffuser. The method of computation is based on the principles developed by Pfleiderer (Forschungsarbeiten No. 295). The practical interest of this investigation arises from the fact that the design of the fan guide elements - vaneless diffusers, guide vanes, spiral casing - is far behind the design of the impeller as regards accuracy and reliability" … more
Date: December 1942
Creator: Polikovsky, V. & Nevelson, M.
Item Type: Refine your search to only Report
open access

Prediction of Downwash and Dynamic Pressure at the Tail From Free-Flight Measurements

Description: "The present measurements form a continuation of earlier flight tests published in a previous report for predicting the downwash at the tail of an airplane. The method makes use of the tail itself as integrating contact surface to the extent that, beginning from the measurement of the self-alignment of the elevator, the mean downwash angle and dynamic pressure at the tail are determined. The instrumental accuracy is considerably improved if the elevator is completely separate from the controls … more
Date: July 1942
Creator: Eujen, E.
Item Type: Refine your search to only Report
open access

Pressure Distribution on Wings in Reversed Flow

Description: "The series of pressure distribution measurements at three test sections on NACA airfoils 2212 and M6 within 170 to 210 angles of attack in reversed flow proved to be largely independent of the profile form. In contradiction to the pressure distribution in normal flow considerable negative pressure from the upper surface spills over onto the lower surface, and vice versa, even in the zone of sound flow. The results are presented as chord-wise pressure and load distribution" (p. 1).
Date: April 1942
Creator: Naumann, A.
Item Type: Refine your search to only Report
open access

Propeller Blade Stresses Caused by Periodic Displacement of the Propeller Shaft

Description: The present report deals with different vibration stresses of the propeller and their removal by an elastic coupling of propeller and engine. A method is described for protecting the propeller from unstable oscillations and herewith from the thus excited alternating gyroscopic moments. The respective vibration equations are set down and the amount of elasticity required is deduced.
Date: June 1942
Creator: Meyer, J.
Item Type: Refine your search to only Report
open access

Recent Results in Rocket Flight Technique

Description: "The concept of the effective ejection velocity of a rocket engine is explained and the magnitude of the attainable ejection velocity theoretically and experimentally investigated. Velocities above 3000 meters per second (6700 mph) are actually measured and the possibilities of further increases shown" (p. 1).
Date: April 1942
Creator: Sänger, Eugen
Item Type: Refine your search to only Report
open access

Recording Rapidly Changing Cylinder-Wall Temperatures

Description: "The present report deals with the design and testing of a measuring plug suggested by H. Pfriem for recording quasi-stationary cylinder wall temperatures. The new device is a resistance thermometer, the temperature-susceptible part of which consists of a gold coating applied by evaporation under high vacuum and electrolytically strengthened. After overcoming initial difficulties, calibration of plugs up to and beyond 400 degrees C was possible" (p. 1).
Date: May 1942
Creator: Meier, Adolf
Item Type: Refine your search to only Report
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