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The use of two-dimensional section data to estimate the low-speed wing lift coefficient at which section stall first appears on a swept wing

Description: Report discusses a procedure for estimating the wing lift coefficient for and spanwise location of the first occurrence of section stall on a swept wing. It has been modified from a method used to calculate the same information for unswept wings. The effects of split flaps, leading-edge modifications, and fences are described.
Date: July 27, 1951
Creator: Maki, Ralph L.
Partner: UNT Libraries Government Documents Department

Experimental investigation of typical constant- and variable-area exhaust nozzles and effects on axial-flow turbojet-engine performance

Description: Report presenting testing of several turbojet engines with both constant- and variable-area nozzles to extend full-scale nozzle performance to higher exhaust-nozzle pressure ratios and to investigate the effects of constant- and variable-area nozzles on turbojet-engine operation. Results regarding the different types of nozzles are provided.
Date: July 9, 1951
Creator: Wallner, Lewis E. & Wintler, John T.
Partner: UNT Libraries Government Documents Department

Investigation at Mach number 1.88 of half of a conical-spike diffuser mounted as a side inlet with boundary-layer control

Description: Experimental investigation was conducted at Mach number 1.88 to determine performance characteristics of half a 50 degree-conical-spike inlet mounted on a flat plate. Initial boundary layer was removed up-stream of inlet by a ram-type scoop of variable height. Initial boundary-layer thickness was also varied. With complete removal of initial boundary layer, total-pressure recovery of approximately 70 percent. Several alternative boundary-layer-removal systems were investigated which decreased the adverse effect of operating the ram scoop sub-critically.
Date: September 19, 1951
Creator: Goelzer, H. Fred & Cortright, Edgar M., Jr.
Partner: UNT Libraries Government Documents Department

The effects at transonic speeds of thickening the trailing edge of a wing with a 4-percent-thick circular-arc airfoil

Description: Report presenting an investigation of the effects of a systematic variation of trailing-edge thickness of a symmetrical, circular-arc airfoil on the aerodynamic force, moment, base-pressure, and wake fluctuations using the transonic-bump testing technique. Results regarding the effects of a systematic variation of the trailing-edge thickness, investigation of a boattailed trailing edge, and wake fluctuation characteristics are provided.
Date: December 11, 1951
Creator: Cleary, Joseph W. & Stevens, George L.
Partner: UNT Libraries Government Documents Department

Effect of the proximity of the ground on the stability and control characteristics of a vertically rising airplane model in the hovering condition

Description: Report discussing the effect of the proximity of the ground on the stability and control characteristics of a vertically rising airplane model in the hovering condition. The dynamic behavior of the model in take-offs and landings and when it was hovering near the ground was also investigated. Force tests to determine the change in the vertical-tail yawing moments with control deflection and with angle of yaw for various heights were also conducted.
Date: September 19, 1951
Creator: Smith, Charles C., Jr.; Lovell, Powell M., Jr. & Bates, William R.
Partner: UNT Libraries Government Documents Department

An investigation of the control-surface flutter derivatives of an NACA 65(sub 1)-213 airfoil in the Ames 16-foot high-speed wind tunnel

Description: Report presenting a determination of control-surface flutter derivatives for a sinusoidally oscillating control surface mounted on a two-dimensional fixed airfoil for a range of reduced frequency. Results regarding subsonic results and transonic results are provided.
Date: December 21, 1951
Creator: Wyss, John A. & Sorenson, Robert M.
Partner: UNT Libraries Government Documents Department

Experimental investigation of turbojet-engine thrust augmentation by combined compressor coolant injection and tail-pipe burning

Description: Report presenting an investigation of combined compressor coolant injection and tailpipe burning as a means of turbojet engine thrust augmentation at sea-level, zero ram conditions on a 4000 pound thrust, axial-flow-type turbojet engine. Water-alcohol injection flows from 2 to 5 pounds per second were introduced into the compressor in conjunction with tail-pipe burner fuel-air ratios from 0.017 to stoichiometric. Results regarding engine performance and operational characteristics are provided.
Date: October 17, 1951
Creator: Useller, James W. & Povolny, John H.
Partner: UNT Libraries Government Documents Department

Free-flight investigation to determine force and hinge-moment characteristics at zero angle of attack of a 60 degrees sweptback half-delta tip control on a 60 degrees sweptback delta wing at Mach numbers between 0.68 and 1.44

Description: Report presenting a free-flight investigation of two rocket-powered control research models to determine the force and hinge-moment characteristics at zero angle of attack of a half-delta tip control on a delta wing. Results regarding the control hinge moments, control normal force, and calculated hinge moments are provided.
Date: December 3, 1951
Creator: Martz, C. William; Church, James D. & Goslee, John W.
Partner: UNT Libraries Government Documents Department

Investigation of a 24-inch shock-in-rotor type supersonic compressor designed for simple radial equilibrium behind normal shock

Description: A 24-inch-diameter shock-in-rotor supersonic compressor rotor designed to obtain simple radial equilibrium behind the normal shock obtained a maximum total-pressure ratio of 2.02 at an adiabatic efficiency of 0.74 and a weight flow of 61.5 pounds per second at design speed. Although this design method considerably reduced the radial forces, there was no apparent reduction in the radial forces, there was no apparent reduction in the radial redistribution of mass flow over the radial redistribution obtained in the previous investigation. This investigation indicates that the shock boundary-layer interaction pattern and associated effects have a very large effect on the radial redistribution of mass flow through the shock-in-rotor supersonic-compressor rotor.
Date: December 12, 1951
Creator: Lown, Harold & Hartmann, Melvin J.
Partner: UNT Libraries Government Documents Department

A two-dimensional cascade study of the aerodynamic characteristics of a turbine-rotor blade suitable for air cooling

Description: Report presenting an investigation of the aerodynamic problems associated with turbine blades with relatively low solidity and thick profiles, which makes them suitable for use in air-cooled turbines, in a two-dimensional cascade. Testing indicated that supersonic velocities may be obtained over the greater portion of the blade suction surface, resulting in high blade loading without an appreciable decrease in efficiency from that obtained using blades with lower velocities.
Date: September 20, 1951
Creator: Plohr, Henry W. & Hauser, Cavour H.
Partner: UNT Libraries Government Documents Department

Two-dimensional cascade investigation of the maximum exit tangential velocity component and other flow conditions at the exit of several turbine blade designs at supercritical pressure ratios

Description: The nature of the flow at the exit of a row of turbine blades for the range of conditions represented by four different blade configurations was evaluated by the conservation-of-momentum principle using static-pressure surveys and by analysis of Schlieren photographs of the flow. It was found that for blades of the type investigated, the maximum exit tangential-velocity component is a function of the blade geometry only and can be accurately predicted by the method of characteristics. A maximum value of exit velocity coefficient is obtained at a pressure ratio immediately below that required for maximum blade loading followed by a sharp drop after maximum blade loading occurs.
Date: August 23, 1951
Creator: Hauser, Cavour H. & Plohr, Henry W.
Partner: UNT Libraries Government Documents Department

Base pressures measured on several parabolic-arc bodies of revolution in free flight at Mach numbers from 0.8 to 1.4 and at large Reynolds numbers

Description: Report presenting base pressures measured on several fin-stabilized bodies of parabolic-arc profile in free flight at a range of Mach and Reynolds numbers. The bodies varied in length but had the same afterbody ratios. Results regarding base pressure coefficients, side pressure coefficients, effect of afterbody length, and drag are provided.
Date: October 26, 1951
Creator: Katz, Ellis & Stoney, William E., Jr.
Partner: UNT Libraries Government Documents Department

Preliminary results of turbojet-engine altitude-starting investigation

Description: A spark energy of 2.13 joules per spark at 1 spark per second produced ignition to an altitude of 50,000 feet at a flight Mach number of 0.6. The minimum power requirements for ignition were obtained from a combination of low spark repetition rates and high spark energy. The altitude-ignition limit was also increased by increasing spark-gap immersion, fuel temperature, inlet-air temperature, and fuel volatility, and by decreasing flight Mach number. The maximum altitude at which flame propagation was accomplished from combusters with spark plugs to combusters without spark plugs to combustors without spark plugs was increased about 5000 feet by increasing fuel volatility.
Date: November 5, 1951
Creator: Wilsted, H. D. & Armstrong, J. C.
Partner: UNT Libraries Government Documents Department

Performance of single-stage compressor designed on basis of constant total enthalpy with symmetrical velocity diagram at all radii and velocity ratio of 0.7 at rotor hub

Description: A typical inlet axial-flow compressor inlet stage, which was designed on the basis of constant total enthalpy with symmetrical velocity diagram at all radii, was investigated. At a tip speed of 1126 feet per second, a peak pressure ratio of 1.28 was obtained at an efficiency of 0.76. At a tip speed, the highest practical flow was 28 pounds per second per square foot frontal area with an efficiency of 0.78. Data for a rotor relative inlet Mach number range of from 0.5 to 0.875 indicates that the critical value for any stage radial element is approximately 0.80 for the stage investigated.
Date: September 6, 1951
Creator: Burtt, Jack R. & Jackson, Robert J.
Partner: UNT Libraries Government Documents Department

Altitude-performance and Reynolds number investigation of centrifugal-flow-compressor turbojet engine

Description: From Introduction: "Altitude-chamber and wind-tunnel investigations of the performance of turbojet engines such as those reported in references 1 to 4 have shown that the conventional correction factors fail to generalize the engine performance variables at high altitudes. An investigation was therefore made at the NACA Lewis laboratory to determine the altitude performance of the J33-A-23 turbojet engine and to demonstrate the magnitude of departure of actual altitude performance from that predicted from sea-level performance."
Date: May 15, 1951
Creator: Wilsted, H. D. & Grey, R. E.
Partner: UNT Libraries Government Documents Department

Load distribution over a fuselage in combination with a swept wing at small angles of attack and transonic speeds

Description: Report presenting free-fall tests of a wing-body configuration with a 45 degree sweptback cambered and twisted wing of aspect ratio 6 on a fuselage of fineness ratio 12.4. Results regarding the load and pitching moments and load-coefficient distribution are provided.
Date: November 27, 1951
Creator: White, Maurice D. & Look, Bonne C.
Partner: UNT Libraries Government Documents Department

Analytical investigation of flow through high-speed mixed-flow turbine

Description: From Introduction: "Good experimental correlation of the analytical results was obtained for the compressor even though isentropic flow and axial symmetry were assumed (reference 1). In order to determine the flow through the turbine being investigated, however, it was necessary to extend the method of reference 1 to include the flow downstream of the rooter since the large blade taper and hub-shroud curvature caused downstream conditions which affected the flow inside the rotor."
Date: October 3, 1951
Creator: Stewart, Warner L.
Partner: UNT Libraries Government Documents Department

Characteristics of a Transonic Test Section With Various Slot Shapes in the Langley 8-Foot High-Speed Tunnel

Description: Report presenting a large wind tunnel that has been converted to transonic operation by means of slots in the boundary extending in the direction of flow. The usefulness of a slotted wind tunnel has been augmented by devising a slot shape with which a supersonic test region with excellent flow quality can be produced.
Date: October 18, 1951
Creator: Wright, Ray H. & Ritchie, Virgil S.
Partner: UNT Libraries Government Documents Department

A Preliminary Investigation of Combustion With Rotating Flow in an Annular Combustion Chamber

Description: Memorandum presenting a preliminary investigation of flame-stability and flame-extinction characteristics of a propane-air mixture in an annular combustion chamber conducted with both straight and rotational flow. The rotating mixture burned at higher axial-inlet stream velocities and with more stable flames than could be obtained with straight-flow burning.
Date: September 18, 1951
Creator: Schwartz, Ira R.
Partner: UNT Libraries Government Documents Department

Fundamental Flame Velocities of Pure Hydrocarbons 3: Extension of Tube Method of High Flame Velocities - Acetylene-Air Mixtures

Description: Memorandum presenting an extension of the tube method of measuring flame velocities to fundamental flame velocities of 141 centimeters per second. The extension was accomplished by reducing the flame-tube diameter from 25 to 12.5 millimeters. Results regarding the gas flow and spatial flame velocity, flame surface area, and fundamental flame velocity are provided.
Date: December 3, 1951
Creator: Levine, Oscar & Gerstein, Melvin
Partner: UNT Libraries Government Documents Department

Preliminary Results of a Determination of Temperatures of Flames by Means of K-Band Microwave Attenuation

Description: "The temperature effects on the attenuation of K-band microwaves, at a frequency of 26,500 plus or minus 30 megacycles per second, through natural-gas and propane flames containing added alkali halide salts, were investigated over a temperature range from 1900 to 2500 K. The preliminary data of this investigation indicated that the attenuation varies appreciably with the sodium-line-reversal temperatures of the flames and is independent of the particular hydrocarbon fuels that were used for temperature sources and of the particular halide components of the compounds used in the concentrations employed to produce easily measurable attenuation. A reproducibility of plus or minus 25 K was obtainable" (p. 1).
Date: September 24, 1951
Creator: Rudlin, Leonard
Partner: UNT Libraries Government Documents Department

A Relation of Wind Shear and Insolation to the Turbulence Encountered by an Airplane in Clear-Air Flight at Low Altitudes

Description: Memorandum presenting the observed gust experience of an airplane and information on the associated meteorological conditions to obtain a simple empirical relation for estimating the intensity of turbulence in the earth's friction layer. The relation does not discriminate between differences in turbulence intensity resulting from variations of flight altitude or diurnal variations of turbulence.
Date: September 13, 1951
Creator: Thompson, James K.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Forced-Convection Heat-Transfer Characteristics of Lead-Bismuth Eutectic

Description: The forced-convection heat-transfer characteristics of lead-bismuth eutectic were experimentally investigated. Experimental values of Nusselt number for lead-bismuth fell considerably below predicted values. The addition of a wetting agent did not change the heat transfer characteristics.
Date: September 20, 1951
Creator: Lubarsky, Bernard
Partner: UNT Libraries Government Documents Department

Estimation of Neutron Energy for First Resonance From Absorption Cross Section for Thermal Neutrons

Description: Examination of published data for some 52 isotopes indicates that the neutron energy for which the first resonance occurs is related to the magnitude of the thermal absorption cross section. The empirical relation obtained is in qualitative agreement with the results of a simplified version of the resonance theory of the nucleus of Breit-Wigner.
Date: September 17, 1951
Creator: Bogart, Donald
Partner: UNT Libraries Government Documents Department