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  Partner: UNT Libraries Government Documents Department
 Collection: National Advisory Committee for Aeronautics Collection
High-speed wind tunnels

High-speed wind tunnels

Date: November 1, 1936
Creator: Ackeret, J
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.
Contributing Partner: UNT Libraries Government Documents Department
Present and future problems of airplane propulsion

Present and future problems of airplane propulsion

Date: May 1, 1941
Creator: Ackeret, J
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.
Contributing Partner: UNT Libraries Government Documents Department
Recent experiments at the Gottingen Aerodynamic Institute

Recent experiments at the Gottingen Aerodynamic Institute

Date: July 1, 1925
Creator: Ackeret, J
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).
Contributing Partner: UNT Libraries Government Documents Department
Removing boundary layer by suction

Removing boundary layer by suction

Date: January 1, 1927
Creator: Ackeret, J
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.
Contributing Partner: UNT Libraries Government Documents Department
Experimental and Theoretical Investigations of Cavitation in Water

Experimental and Theoretical Investigations of Cavitation in Water

Date: May 1, 1945
Creator: Ackeret, J.
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.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic Heat-Power Engine Operating on a Closed Cycle

Aerodynamic Heat-Power Engine Operating on a Closed Cycle

Date: November 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.
Contributing Partner: UNT Libraries Government Documents Department
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.
Contributing Partner: UNT Libraries Government Documents Department
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 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.
Contributing Partner: UNT Libraries Government Documents Department
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.
Contributing Partner: UNT Libraries Government Documents Department
Flight measurements of the effect of various amounts of aileron droop on the low-speed lateral-control characteristics of an observation airplane

Flight measurements of the effect of various amounts of aileron droop on the low-speed lateral-control characteristics of an observation airplane

Date: August 18, 1943
Creator: Adams, Betty
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Flight measurements of the effects of a wing leading-edge slot and other modifications on the stability, maximum lift, and high speed of an observation airplane

Flight measurements of the effects of a wing leading-edge slot and other modifications on the stability, maximum lift, and high speed of an observation airplane

Date: January 19, 1943
Creator: Adams, Betty
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Theoretical damping in roll and rolling moment due to differential wing incidence for slender cruciform wings and wing-body combinations

Theoretical damping in roll and rolling moment due to differential wing incidence for slender cruciform wings and wing-body combinations

Date: January 1, 1952
Creator: Adams, Gaynor J & DUGAN DUANE W
Description: A method of analysis based on slender-wing theory is developed to investigate the characteristics in roll of slender cruciform wings and wing-body combinations. The method makes use of the conformal mapping processes of classical hydrodynamics which transform the region outside a circle and the region outside an arbitrary arrangement of line segments intersecting at the origin. The method of analysis may be utilized to solve other slender cruciform wing-body problems involving arbitrarily assigned boundary conditions. (author).
Contributing Partner: UNT Libraries Government Documents Department
Flying qualities of a high-performance personal-owner airplane

Flying qualities of a high-performance personal-owner airplane

Date: November 8, 1951
Creator: Adams, James J & Lhitten, James B
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Theoretical study of the lateral frequency response to gusts of a fighter airplane, both with controls fixed and with several types of autopilots

Theoretical study of the lateral frequency response to gusts of a fighter airplane, both with controls fixed and with several types of autopilots

Date: March 1, 1956
Creator: Adams, James J & Mathews, Charles, W
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Tests of a centering spring used as an artificial feel device on the elevator of a fighter airplane

Tests of a centering spring used as an artificial feel device on the elevator of a fighter airplane

Date: September 12, 1952
Creator: Adams, James J & Whitten, James B
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Determination of Shapes of Boattail Bodies of Revolution for Minimum Wave Drag

Determination of Shapes of Boattail Bodies of Revolution for Minimum Wave Drag

Date: November 1, 1951
Creator: Adams, Mac C.
Description: By use of an approximate equation for the wave drag of slender bodies of revolution in a supersonic flow field, the optimum shapes of certain boattail bodies are determined for minimum wave drag. The properties of three specific families of bodies are determined, the first family consisting of bodies having a given length and base area and a contour passing through a prescribed point between the nose and base, the second family having fixed length, base area, and maximum area, and the third family having given length, volume, and base area. The method presented is easily generalized to determine minimum-wave-drag profile shapes which have contours that must pass through any prescribed number of points. According to linearized theory, the optimum profiles are found to have infinite slope at the nose but zero radius of curvature so that the bodies appear to have pointed noses, a zero slope at the body base, and no variation of wave drag with Mach number. For those bodies having a specified intermediate.diameter (that is, location and magnitude given), the maximum body diameter is shown to be larger, in general, than the specified diameter. It is also shown that, for bodies having a specified maximum diameter, ...
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Flight investigation of the effect of a local change in wing contour on chordwise pressure distribution at high speeds

Flight investigation of the effect of a local change in wing contour on chordwise pressure distribution at high speeds

Date: September 1, 1946
Creator: Adams, Richard E & Silsby, Norman S
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Tests of a Horizontal-Tail Model through the Transonic Speed Range by the NACA Wing-Flow Method

Tests of a Horizontal-Tail Model through the Transonic Speed Range by the NACA Wing-Flow Method

Date: April 11, 1947
Creator: Adams, Richard E. & Silsby, Norman S.
Description: A 1/12-scale model of a horizontal tail of a fighter airplane was tested through the transonic speeds in the high-speed flow over an airplane wing, the surface of which served as a reflection plane for the model. Measurements of lift, elevator-hinge moment, angle of attack, and elevator angle were made in the Mach number range from 0.75 to 1.04 for elevator deflections ranging from 10 degrees to minus 10 degrees, and for angles of attack of minus 1.2 degrees, 0.4 degrees, and 3.4 degrees. The equipment used to measure the hinge moments of the model proved to be unsatisfactory, and for this reason the hinge-moment data are considered to be only qualitative.
Contributing Partner: UNT Libraries Government Documents Department
Investigation of Downwash, Sidewash, and Mach Number Distribution behind a Rectangular Wing at a Mach Number of 2.41

Investigation of Downwash, Sidewash, and Mach Number Distribution behind a Rectangular Wing at a Mach Number of 2.41

Date: September 14, 1950
Creator: Adamson, D. & Boatright, William B.
Description: An investigation of the nature of the flow field behind a rectangular circular-arc wing has been conducted in the Langley 9-inch supersonic tunnel. Pitot- and static-pressure surveys covering a region of flow behind the wing have been made together with detailed pitot surveys throughout the region of the wake. In addition, the flow direction has been measured using a weathercocking vane measurements. Theoretical calculations of the variation of both downwash and sidewash with angle of attack using Lagerstrom's superposition method have been made. In addition the effect of the wing thickness on the sidewash with the wing at 0 angle of attack has been evaluated. Near an angle of attack of 0, agreement between theory and experiment is good, particularly for the downwash results, except in the plane of the wing, inboard of the tip. In this region the proximity of the shed vortex sheet and the departure of the spanwise distribution of vorticity from theory would account for the disagreement. At higher angles of attack prediction of downwash depends on a knowledge of the location of the trailing vortex sheet, in order that the downwash may be corrected for its displacement and distortion. The theoretical location of the trailing ...
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Investigation of downwash, sidewash, and Mach number distribution behind a rectangular wing at a Mach number of 2.41

Investigation of downwash, sidewash, and Mach number distribution behind a rectangular wing at a Mach number of 2.41

Date: January 1, 1957
Creator: Adamson, David & Boatright, William B
Description: An investigation of the nature of the flow field behind a rectangular wing of circular arc cross section has been conducted in the Langley 9-inch supersonic tunnel. Pitot- and static-pressure surveys covering a region of flow behind the wing have been made together with detailed pitot surveys throughout the region of the wake. In addition, the flow direction has been measured by means of a weathercocking vane. Theoretical calculations have been made to obtain the variation of both downwash and sidewash with angle of attack by using the superposition method of Lagerstrom, Graham, and Grosslight. In addition, the effect of wing thickness on the sidewash with the wing at 0 degree angle of attack has been evaluated.
Contributing Partner: UNT Libraries Government Documents Department
Characteristics of the BMW 801D2 automatic engine control as determined from bench tests

Characteristics of the BMW 801D2 automatic engine control as determined from bench tests

Date: April 1, 1945
Creator: Addie, A N
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Effects of combinations of aspect ratio and sweepback at high subsonic Mach numbers

Effects of combinations of aspect ratio and sweepback at high subsonic Mach numbers

Date: June 4, 1947
Creator: Adler, Alfred A
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Variation with Mach Number of Static and Total Pressures Through Various Screens

Variation with Mach Number of Static and Total Pressures Through Various Screens

Date: February 1, 1946
Creator: Adler, Alfred A
Description: Tests were conducted in the Langley 24-inch highspeed tunnel to ascertain the static-pressure and total-pressure losses through screens ranging in mesh from 3 to 12 wires per inch and in wire diameter from 0.023 to 0.041 inch. Data were obtained from a Mach number of approximately 0.20 up to the maximum (choking) Mach number obtainable for each screen. The results of this investigation indicate that the pressure losses increase with increasing Mach number until the choking Mach number, which can be computed, is reached. Since choking imposes a restriction on the mass rate of flow and maximum losses are incurred at this condition, great care must be taken in selecting the screen mesh and wire dimmeter for an installation so that the choking Mach number is.
Contributing Partner: UNT Libraries Government Documents Department
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.
Contributing Partner: UNT Libraries Government Documents Department