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  Partner: UNT Libraries Government Documents Department
 Serial/Series Title: NACA Technical Memorandums
 Collection: National Advisory Committee for Aeronautics Collection
Aerodynamic Heat-Power Engine Operating on a Closed Cycle

Aerodynamic Heat-Power Engine Operating on a Closed Cycle

Date: November 1, 1942
Creator: Ackeret, J. & Keller, D. C.
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 which the internal efficiency of the unit changes but slightly. The effect of pressure and temperature losses is investigated. A general discussion is given of the experimental installation operating at the Escher Wyss plant in Zurich for a considerable time at high temperatures.
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Investigations of Compression Shocks and Boundary Layers in Gases Moving at High Speed

Investigations of Compression Shocks and Boundary Layers in Gases Moving at High Speed

Date: January 1, 1947
Creator: Ackeret, J.; Feldmann, F. & Rott, N.
Description: The mutual influences of compression shocks and friction boundary layers were investigated by means of high speed wind tunnels.Schlieren optics provided a clear picture of the flow phenomena and were used for determining the location of the compression shocks, measurement of shock angles, and also for Mach angles. Pressure measurement and humidity measurements were also taken into consideration.Results along with a mathematical model are described.
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Experiments with an airfoil from which the boundary layer is removed by suction

Experiments with an airfoil from which the boundary layer is removed by suction

Date: August 1, 1926
Creator: Ackeret, J; Betz, A & Schrenk, O
Description: Our attempts to improve the properties of airfoils by removing the boundary layer by suction, go back to 1922. The object of the suction is chiefly to prevent the detachment of the boundary layer from the surface of the airfoil. At large angles of attack, such detachment prevents the attainment of the great lift promised by the theory, besides greatly increasing the drag, especially of thick airfoils. This report gives results of those experiments.
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Investigations on wings with and without sweepback at high subsonic speeds

Investigations on wings with and without sweepback at high subsonic speeds

Date: November 1, 1951
Creator: Ackeret, Jakob; Rott, Nikolaus & Degen, Max
Description: Drag tests at zero lift have been made at Mach numbers from 0.7 to approximately 0.95 in the high speed wind tunnel of the Institute of Aerodynamics, ETH, Zurich, on a group of untapered wings of aspect ratio 3.25, having sweep angles of 0 degree and 35 degrees. For each sweep angle, a series of geometrically similar models was tested at a constant Reynolds number to provide a verification of computed tunnel blocking corrections. Tests were also made for wings having thickness ratios of 0.09 and 0.12 and the results compared with results predicted by von Karman's similarity law.
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The Magnus effect in theory and in reality

The Magnus effect in theory and in reality

Date: May 1, 1930
Creator: Ahlborn, F
Description: A discussion of the Flettner rotor is presented from a nautical and economic viewpoint, and although it was a failure, the experimental and theoretical inventions cannot be disregarded. The following critical and experimental investigation will show the relations and applicability of the theories and practical applications. The Magnus effect is described in detail and a discussion and critical review of the Magnus effect is included.
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Turbulence and mechanism of resistance on spheres and cylinders

Turbulence and mechanism of resistance on spheres and cylinders

Date: January 1, 1932
Creator: Ahlborn, FR
Description: The nature of turbulent flow through pipes and around obstacles is analyzed and illustrated by photographs of turbulence on screens and straighteners. It is shown that the reversal of flow and of the resistance law on spheres is not explainable by Prandtl's turbulence in the boundary layer. The investigation of the analogous phenomena on the cylinder yields a reversal of the total field of flow. The very pronounced changes in pressure distribution connected with it were affirmed by manometric measurements on spheres by Professor O. Krell. The reversal in a homogenous nonvortical flow is brought about by the advance of the stable arrangement of Karman's dead air vortices toward the test object and by the substitution of an alternatingly one-sided or rotating but stable vortex formation in place of the initially symmetrical formation. This also explains the marked variations of the models.
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Experimental determination of local and mean coefficients of heat transfer for turbulent flow in pipes

Experimental determination of local and mean coefficients of heat transfer for turbulent flow in pipes

Date: February 1, 1954
Creator: Aladyev, I T
Description: An extensive investigation of the changes of the local and mean heat-transfer coefficients along the pipe length, and some results.
Contributing Partner: UNT Libraries Government Documents Department
Air cooling : an experimental method of evaluating the cooling effect of air streams on air-cooled cylinders

Air cooling : an experimental method of evaluating the cooling effect of air streams on air-cooled cylinders

Date: May 1, 1927
Creator: Alcock, J F
Description: In this report is described an experimental method which the writer has evolved for dealing with air-cooled engines, and some of the data obtained by its means. Methods of temperature measurement and cooling are provided.
Contributing Partner: UNT Libraries Government Documents Department
Combustion of liquid fuels in diesel engine

Combustion of liquid fuels in diesel engine

Date: October 1, 1924
Creator: Alt, Otto
Description: Hitherto, definite specifications have always been made for fuel oils and they have been classified as more or less good or non-utilizable. The present aim, however, is to build Diesel engines capable of using even the poorest liquid fuels and especially the waste products of the oil industry, without special chemical or physical preparation.
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On the Calculation of Shallow Shells

On the Calculation of Shallow Shells

Date: December 1, 1956
Creator: Ambartsumyan, S. A.
Description: This paper considers a sufficiently thin shallow shell of nonzero Gaussian curvature. It also presents a system of symmetrically constructed differential equations, constructed by the mixed method through the stress function and the displpacement function.
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