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Air forces on airfoils moving faster than sound

Description: We are undertaking the task of computing the air forces on a slightly cambered airfoil in the absence of friction and with an infinite aspect ratio. We also assume in advance that the leading edge is very sharp and that its tangent lies in the direction of motion.
Date: June 1925
Creator: Ackeret, J
Item Type: Report
Partner: UNT Libraries Government Documents Department

Drag measurements of two thin wing sections at different index values

Description: It is stated that the index value 6000, as found in normal tests of wing sections with a 20 cm chord, falls in the same region where the transition of laminar to turbulent flow takes place on thin flat plates. It is to be expected that slightly cambered, thin wing sections will behave similarly. The following test of two such wing sections were made for the purpose of verifying this supposition.
Date: June 1, 1927
Creator: Ackeret, J
Item Type: Report
Partner: UNT Libraries Government Documents Department

Experiments on airfoils with trailing edge cut away

Description: Airfoils with their trailing edge cut away are often found on aircraft, as the fins on the hulls of flying boats and the central section of the wings for affording better visibility. It was therefore of some interest to discover the effect of such cutaways on the lift and drag and on the position of the center of pressure. For this purpose, systematic experiments were performed on two different airfoils, a symmetrical airfoil and an airfoil of medium thickness, with successive shortenings of their chords.
Date: September 1, 1927
Creator: Ackeret, J
Item Type: Report
Partner: UNT Libraries Government Documents Department

High-speed wind tunnels

Description: Wind tunnel construction and design is discussed especially in relation to subsonic and supersonic speeds. Reynolds Numbers and the theory of compressible flows are also taken into consideration in designing new tunnels.
Date: November 1, 1936
Creator: Ackeret, J
Item Type: Report
Partner: UNT Libraries Government Documents Department

Present and future problems of airplane propulsion

Description: Some of the problems considered in this report include: thermodynamics of surface friction, application of thick wing sections, special applications of controllable propellers, and gas turbines for aircraft.
Date: May 1, 1941
Creator: Ackeret, J
Item Type: Report
Partner: UNT Libraries Government Documents Department

Removing boundary layer by suction

Description: Through the utilization of the "Magnus effect" on the Flettner rotor ship, the attention of the public has been directed to the underlying physical principle. It has been found that the Prandtl boundary-layer theory furnishes a satisfactory explanation of the observed phenomena. The present article deals with the prevention of this separation or detachment of the flow by drawing the boundary layer into the inside of a body through a slot or slots in its surface.
Date: January 1, 1927
Creator: Ackeret, J
Item Type: Report
Partner: UNT Libraries Government Documents Department

Experimental and Theoretical Investigations of Cavitation in Water

Description: The cavitation in nozzles on airfoils of various shape and on a sphere are experimentally investigated. The limits of cavitation and the extension of the zone of the bubbles in different stages of cavitation are photographically established. The pressure in the bubble area is constant and very low, jumping to high values at the end of the area. The analogy with the gas compression shock is adduced and discussed. The collapse of the bubbles under compression shock produces very high pressures internally, which must be contributory factors to corrosion. The pressure required for purely mechanical corrosion is also discussed.
Date: May 1, 1945
Creator: Ackeret, J.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Recent experiments at the Gottingen Aerodynamic Institute

Description: This report presents the results of various experiments carried out at the Gottingen Aerodynamic Institute. These include: experiments with Joukowski wing profiles; experiments on an airplane model with a built-in motor and functioning propeller; and the rotating cylinder (Magnus Effect).
Date: July 1, 1925
Creator: Ackeret, J.
Item Type: Report
Partner: UNT Libraries Government Documents Department

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 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.
Date: November 1942
Creator: Ackeret, J. & Keller, D. C.
Item Type: Report
Partner: UNT Libraries Government Documents Department

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

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.
Date: January 1, 1947
Creator: Ackeret, J.; Feldmann, F. & Rott, N.
Item Type: Report
Partner: UNT Libraries Government Documents Department

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

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.
Date: August 1926
Creator: Ackeret, J; Betz, A & Schrenk, O
Item Type: Report
Partner: UNT Libraries Government Documents Department

Investigations on wings with and without sweepback at high subsonic speeds

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.
Date: November 1, 1951
Creator: Ackeret, Jakob; Rott, Nikolaus & Degen, Max
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development Progress Report: April-June 1983

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts on development of molten carbonate fuel cells directed toward seeking alternative cathode materials to NiO. Based on an investigation of the thermodynamically stable phases formed under cathode conditions with a number of transition metal oxides, synthesis of prospective alternative cathode materials and doping of these materials to promote electronic conductivity is under way.
Date: February 1984
Creator: Ackerman, J. P. & Pierce, Robert Dean
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development Progress Report: January-March 1978

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes the development of electrolyte structures which have good electrolyte retention and mechanical properties as well as long term stability, and on developing methods of synthesis amenable to mass production.
Date: 1977?
Creator: Ackerman, J. P.; Ackerman, J. P.; Pierce, Robert Dean; Nelson, P. A.; Arons, R. M.; Kinoshita, K. et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development Progress Report: October-December 1977

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes work aimed at understanding and improving the performance of fuel cells having molten alkali-carbonate mixtures as electrolytes; the fuel cells operate at temperatures near 925 K.
Date: March 1978
Creator: Ackerman, J. P.; Kinoshita, K.; Finn, P. A.; Sim, J. W. & Nelson, P. A.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development Progress Report: April-June 1977

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes activities directed toward understanding and improvement of molten-carbonate-electrolyte fuel cells operating at temperatures near 923 Kelvin.
Date: August 1977
Creator: Ackerman, J. P.; Pierce, R. D.; Nelson, P. A. & Arons, R. M.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development Progress Report: July-September 1983

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes activities seeking alternative cathode materials to NiO for molten carbonate fuel cells.
Date: June 1984
Creator: Ackerman, J. P.; Pierce, Robert Dean; Nelson, P. A. & Arons, R. M.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development Progress Report: July-September 1984

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes studies directed toward seeking alternative cathode materials to NiO for molten carbonate fuel cells.
Date: June 1985
Creator: Ackerman, J. P.; Pierce, Robert Dean; Nelson, P. A. & Arons, R. M.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development Progress Report: October-December 1983

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes activities directed toward seeking alternative cathode materials to NiO for molten carbonate fuel cells.
Date: August 1984
Creator: Ackerman, J. P.; Pierce, Robert Dean; Nelson, P. A. & Arons, R. M.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development Progress Report: April-June 1978

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes efforts directed toward understanding and improving the components of molten-carbonate-electrolyte fuel cells operated at temperatures near 925 K.
Date: August 1978
Creator: Ackerman, J. P.; Pierce, Robert Dean; Nelson, P. A.; Arons, R. M.; Kinoshita, K.; Sim, J. W. et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Advanced Fuel Cell Development: Progress Report for July-September 1978

Description: Quarterly report discussing fuel cell research and development work at Argonne National Laboratory (ANL). This report describes activities focuses on the development of electrolyte structures that have good electrolyte retention and mechanical properties as well as long term stability, and on developing methods of synthesis amenable to mass production.
Date: May 1979
Creator: Ackerman, J. P.; Pierce, Robert Dean; Nelson, P. A.; Arons, R. M.; Kinoshita, K.; Sim, J. W. et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department