Preliminary investigation of the pressure fluctuations in the wakes of two-dimensional wings at low angles of attack (open access)

Preliminary investigation of the pressure fluctuations in the wakes of two-dimensional wings at low angles of attack

Report presenting a measurement of the magnitudes of pressure fluctuations in the turbulent wakes of restrained two-dimensional airfoils at transonic speeds. Measurements indicated that the total-pressure fluctuations occurred only within the wake. Results regarding the magnitude of pressure oscillation in the wake, effect stream-angle fluctuations in the wake, and frequencies of pressure oscillation on the wing and in the wake are provided.
Date: October 30, 1951
Creator: Sorenson, Robert M.; Wyss, John A. & Kyle, James C.
System: The UNT Digital Library
Preliminary evaluation of the air and fuel specific-impulse characteristics of several potential ram-jet fuels 1: octene-1, aluminum, and aluminum - octene-1 slurries (open access)

Preliminary evaluation of the air and fuel specific-impulse characteristics of several potential ram-jet fuels 1: octene-1, aluminum, and aluminum - octene-1 slurries

Report presenting a preliminary analytical evaluation of the air and fuel specific-impulse characteristics of octene-1, aluminum, and aluminum-octene-1 slurries. The adiabatic combustion flame temperature, combustion equilibrium-gas composition, air specific impulse, and fuel-weight specific impulse are presented for each fuel. Aluminum-octene-1 slurries were found to offer a means of increasing the limited air specific impulse values available with octene-1 or hydrocarbon-type fuels.
Date: April 30, 1951
Creator: Gammon, Benson E.
System: The UNT Digital Library
Effect of Fuel Volatility on Performance of Tail-Pipe Burner (open access)

Effect of Fuel Volatility on Performance of Tail-Pipe Burner

Fuels having Reid vapor pressures of 6.3 and 1.0 pounds per square inch were investigated in a tail-pipe burner on an axial-flow-type turbojet engine at a simulated flight Mach number of 0.6 and altitudes from 20,000 to 45,000 feet. With the burner configuration used in this investigation, having a mixing length of only 8 inches between the fuel manifold and the flame holder, the low-vapor-pressure fuel gave lower combustion efficiency at a given tail-pipe fuel-air ratio. Because the exhaust-nozzle area was fixed, the lower efficiency resulted in lower thrust and higher specific fuel consumption. The maximum altitude at which the burner would operate was practically unaffected by the change in fuel volatility.
Date: April 30, 1951
Creator: Barson, Zelmar & Sargent, Arthur F., Jr.
System: The UNT Digital Library
Design and performance of an experimental axial-discharge mixed-flow compressor 3: over-all performance of impeller and supersonic-diffuser combination (open access)

Design and performance of an experimental axial-discharge mixed-flow compressor 3: over-all performance of impeller and supersonic-diffuser combination

Report presenting an investigation of an axial-discharge impeller in combination with a 16-vaned supersonic diffuser cascade over a range of flow conditions at equivalent tip speeds varying from 800 to 1600 feet per second. Results regarding the overall performance of the combination, starting of diffuser cascade, use of flow bleedoff to aid starting, radial distribution of flow angle, flow characteristics within diffuser, and efficiency of diffuser cascade are provided.
Date: April 30, 1951
Creator: Wilcox, Ward W. & Robbins, William H.
System: The UNT Digital Library
The Use of Suction to Prevent Shock-Induced Separation in a Nozzle (open access)

The Use of Suction to Prevent Shock-Induced Separation in a Nozzle

"An investigation was made of the use of suction to prevent shock-induced flow separation in a nozzle formed by a 7.5-percent-thick bump on a wall of a channel. Various transverse and longitudinal suction-slot arrangements and suction through porous surfaces were tested. All these devices were effective in preventing separation, and certain suction-slot arrangements reduced the total power loss, including the power lost in the suction process" (p. 1).
Date: January 30, 1951
Creator: Sterrett, James R.; Dunning, Robert W. & Brevoort, Maurice J.
System: The UNT Digital Library
Summary of Results Obtained by Transonic-Bump Method on Effects of Plan Form and Thickness on Lift and Drag Characteristics of Wings at Transonic Speeds (open access)

Summary of Results Obtained by Transonic-Bump Method on Effects of Plan Form and Thickness on Lift and Drag Characteristics of Wings at Transonic Speeds

Memorandum presenting a summary of the effects of plan form and thickness on the lift and drag characteristics of wings at transonic speeds. The data was obtained during a transonic research program conducted in the high-speed 7- by 10-foot tunnel by the transonic-bump method. Results regarding lift, drag at zero lift, and drag due to lift are provided.
Date: November 30, 1951
Creator: Polhamus, Edward C.
System: The UNT Digital Library
Investigation of the liquid fluorine-liquid diborane propellant combination in a 100-pound-thrust rocket engine (open access)

Investigation of the liquid fluorine-liquid diborane propellant combination in a 100-pound-thrust rocket engine

The experimental performance of liquid fluorine and liquid diborane was investigated in a 100-pound-thrust engine at a combustion pressure of 300 pounds per square inch absolute. Methods of handling and transporting liquid fluorine were developed. It was extremely difficult to obtain satisfactory operation because of the high flame speed and high combustion chamber temperatures. The maximum performance obtained was 280 pound seconds per pound, 88 percent of the theoretical maximum. The theoretical performance was recalculated with revised thermodynamic data, indicating a maximum specific impulse of 311 pound seconds per pound as compared with the previously reported value of 323.
Date: November 30, 1951
Creator: Ordin, Paul M.; Douglass, Howard W. & Rowe, William H.
System: The UNT Digital Library
Calculated Aerodynamic Loadings of M, W, and Delta Wings in Incompressible Flow (open access)

Calculated Aerodynamic Loadings of M, W, and Delta Wings in Incompressible Flow

Report presenting the results of theoretical incompressible-flow calculations of the spanwise lift distributions, lift-curve slopes, spanwise centers of pressure, aerodynamic centers, coefficients of damping in roll, rolling-moment coefficients due to aileron deflection, and induced-drag coefficients of twenty M, W, and delta wings.
Date: August 30, 1951
Creator: Diederich, Franklin W. & Latham, W. Owen
System: The UNT Digital Library
Lift, Drag, and Pitching Moment of Low-Aspect-Ratio Wings at Subsonic and Supersonic Speeds : Plane Tapered Wing of Aspect Ratio 3.1 with 3-Percent-Thick, Biconvex Section (open access)

Lift, Drag, and Pitching Moment of Low-Aspect-Ratio Wings at Subsonic and Supersonic Speeds : Plane Tapered Wing of Aspect Ratio 3.1 with 3-Percent-Thick, Biconvex Section

"A wing-body combination having a plane tapered wing of aspect ratio 3.1 and 3-percent-thick, biconvex sections in streamwise planes has been investigated at both subsonic and supersonic Mach numbers. The lift, drag, and pitching moment of the model are presented for Mach numbers from 0.60 to 0.925 and 1.20 to 1.90 at a Reynolds number of 2.4 million. Results are also presented for Mach numbers from 0.60 to 0.925 and 1.20 to 1.50 at Reynolds numbers of 1.5 million and 3.8 million" (p. 1).
Date: January 30, 1951
Creator: Reese, David E. & Phelps, E. Ray
System: The UNT Digital Library
Results of Flight Tests to Determine Drag of Parabolic and Cone-Cylinder Bodies of Very Large Fineness Ratios at Supersonic Speeds (open access)

Results of Flight Tests to Determine Drag of Parabolic and Cone-Cylinder Bodies of Very Large Fineness Ratios at Supersonic Speeds

Results of a free-flight investigation at supersonic speeds to determine zero-lift drag of a series of bodies of revolution are presented. Configurations tested included two parabolic bodies with fineness ratios of 17.78 and 24.5 and two 8 degree cone-cylinder bodies with fineness ratios of 17.2 and 21.2. Results of previous tests of similar parabolic bodies but with lower fineness ratios are included in this paper for comparison. All bodies for which data are presented in this paper had a base-to-maximum-diameter ratio of 0.437. Calculated drag coefficients are shown for all bodies for which data are presented. (author).
Date: August 30, 1951
Creator: Welsh, Clement J. & de Moraes, Carlos A.
System: The UNT Digital Library