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Effect of inlet-annulus area blockage on over-all performance and stall characteristics of an experimental 15-stage axial-flow compressor

Description: Report presenting an investigation of an experimental 15-stage axial-flow compressor to determine the effect of inlet-annulus area blockage on disrupting the rotating stall and altering the overall performance and stall characteristics of the compressor. It is part of a general investigation to determine how to alleviate the general problems of blade vibration and poor off-design performance associated with compressor rotating stall.
Date: May 11, 1954
Creator: Lucas, James G.; Finger, Harold B. & Filippi, Richard E.
Partner: UNT Libraries Government Documents Department

Investigation of a translating-cone inlet at Mach numbers from 1.5 to 2.0

Description: Report presenting an investigation in the 8- by 6-foot supersonic wind tunnel to evaluate the performance of a translating-cone inlet operated over a range of Mach numbers and angles of attack. The effects of spike projection and internal flow area variation on pressure recovery, external drag, and corrected air-flow variation were determined.
Date: May 11, 1954
Creator: Sterbentz, William H. & Leissler, L. Abbott
Partner: UNT Libraries Government Documents Department

Low-velocity turning as a means of minimizing boundary-layer accumulations resulting from secondary flows within turbine stators

Description: A study of a series of three single-passage nozzles, designed to turn the flow at different velocity levels but to identical outlet conditions, in order to determine whether secondary-flow accumulations of boundary-layer fluids within nozzles could be minimized by use of low-velocity turning. Results indicated that the type of turning with subsequent acceleration is highly effective in minimizing secondary-flow accumulations at the corner where the suction surface joins the end walls.
Date: May 11, 1954
Creator: Stewart, Warner L. & Wong, Robert Y.
Partner: UNT Libraries Government Documents Department

Comparison of two methods of modulating the throat area of convergent plug nozzles

Description: Report presenting an investigation to determine the effect on performance of two methods of throat-area modulation of two convergent plug nozzles. Data were obtained over a range of pressure ratios. Results regarding the performance of the translatable outer-shell-type plug nozzle, performance of the iris-outer-shell-type plug nozzles, sensitivity to throat-area variation, and air-flow parameter are provided.
Date: May 11, 1955
Creator: Krull, H. George & Beale, William T.
Partner: UNT Libraries Government Documents Department

Analysis of factors affecting selection and design of air-cooled single-stage turbines for turbojet engines 4: coolant-flow requirements and performance of engines using air-cooled corrugated-insert blades

Description: Report presenting an investigation of the estimated minimum cooling requirements and related performance of turbojet engines equipped with high-performance single-stage turbines with air-cooled corrugated-insert blades over a range of turbine-inlet temperature, tip speed, and hub-tip radius ratio for Mach number 2 at 50,000 feet. The effects of stress-ratio factor, flight Mach number, altitude, turbine rotor impeller efficiency, and outside heat-transfer coefficient on cooling requirements were also investigated.
Date: May 11, 1955
Creator: Slone, Henry O. & Hubbartt, James E.
Partner: UNT Libraries Government Documents Department

An investigation of the downwash behind a high-aspect-ratio wing with various amounts of sweep in the Langley 8-foot high-speed tunnel

Description: Report presenting measurements of downwash angles at points at two vertical positions at the probable tail location behind a high-aspect-ratio wing with an NACA 65-210 section with no sweep and 30 degrees and 45 degrees of sweepback and sweepforward in conjunction with a fuselage.
Date: May 11, 1948
Creator: Whitcomb, Richard T.
Partner: UNT Libraries Government Documents Department

Experimental sea-level static investigation of a short afterburner

Description: Report presenting a sea-level static investigation to determine the performance and some design principles for a short afterburner. The power section of a 12-stage axial-flow turbojet engine was used and the afterburner was designed to fit within the length required for the tail pipe used on the standard nonafterburning model.
Date: May 11, 1954
Creator: Harp, James L.; Shillito, Thomas B. & Mallett, William E.
Partner: UNT Libraries Government Documents Department

Preliminary Results From Free Jet Tests of a 48-Inch-Diameter Ram-Jet Combustor With an Annular-Piloted Baffle-Type Flameholder

Description: Report presenting an investigation in a free-jet facility of a ramjet engine with an experimental 48-inch-diameter combustor. Three combustor lengths, three lengths of the shroud which separated the bypass air from the burning stream, and four fuel-distribution systems were investigated over a range of fuel-air ratios and a range of engine air flows. Results regarding the engine performance and ignition data, effect of fuel profile on combustion efficiency, total-pressure ratio, and distribution of static pressure in the main air stream are provided.
Date: May 11, 1955
Creator: Rayle, Warren D.; Smith, Ivan D. & Wentworth, Carl B.
Partner: UNT Libraries Government Documents Department

Preliminary Results From Free-Jet Tests of a 48-Inch-Diameter Ram-Jet Combustor With an Annular Can-Type Flame Holder

Description: Report presenting an investigation in an NACA free-jet facility of a ramjet engine with an experimental 48-inch-diameter combustor. Three combustor lengths and three fuel-distribution systems were investigated over a range of fuel-air ratios and at two air flows. Results regarding the combustor performance and ignition data, velocity profile, and starting characteristics are provided.
Date: May 11, 1955
Creator: Wentworth, Carl B.; Dobson, Wilbur F. & Rayle, Warren D.
Partner: UNT Libraries Government Documents Department

High-Subsonic Performance Characteristics and Boundary-Layer Investigations of a 12 10-Inch-Inlet-Diameter Conical Diffuser

Description: Performance and boundary-layer data were taken in a 12 degree 10-inch inlet-diameter conical diffuser of 2:1 exit- to inlet-area ratio. These data were taken for two inlet-boundary-layer conditions. The first condition was that of a thinner inlet boundary later (boundary-layer displacement thickness, delta* approximately equal to 0.034) produced by an inlet section approximately 1 inlet diameter in length between the entrance bell and the diffuser. The second condition was a thicker inlet boundary layer (delta* approximately equal to 0.120) produced by an additional inlet section length of approximately 6 diameters. Longitudinal static-pressure distributions were measured fro wall static orifices. Transverse total- and static-pressure surveys were made at the inlet and exit stations. Boundary-layer velocity distributions were measured at seven stations between the inlet and exit. These data were obtained for a Reynolds number (based on inlet diameter) range of 1 x 10(exp 6) to 3.9 x 10(exp 6). The corresponding Mach number range was from M = 0.2 to choking. At the maximum-power-available condition supersonic flow was obtained as far as 4.5 inches downstream from the diffuser inlet with a maximum Mach number of M approximately equal to 1.5. The total-pressure loss through the diffuser in percentage of inlet dynamic pressure was approximately 2.5 percent for the thinner inlet boundary later and 5.5 percent for the thicker inlet boundary later over the lower subsonic range. These valued increased with increasing flow rate- the values for the thicker inlet boundary later more than those for the thinner inlet boundary layer. The diffuser effectiveness, expressed as the ratio of the actual static-pressure rise to the ideal static-pressure rise, was about 85 percent for the thinner inlet boundary layer and about 67 percent for the thicker inlet boundary later in the lower subsonic range. These values decrease with increasing flow rate. Separated flow ...
Date: May 11, 1950
Creator: Little, B. H., Jr. & Wilbur, Stafford W.
Partner: UNT Libraries Government Documents Department

Preliminary Results of a Flight Investigation of 1/6-Scale Rocket-Powered Models of the Bell MX-776 to Determine Aileron Rolling Effectiveness and Total Drag

Description: "An experimental investigation of the variation of aileron rolling effectiveness and total drag with Mach number has been made using 1/6-scale rocket-propelled models of the Bell MX-776. Three models having constant-chordwise-thickness full-span aileron at approximate deflections of 2 deg, 5 deg, and 15 deg have been flown. Positive control effectiveness over the Mach number range between approximately 0.5 and 1.2 was obtained from the models and no indication of reversal of effectiveness was encountered" (p. 1).
Date: May 11, 1951
Creator: Stevens, Joseph E.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation at Mach numbers of 1.5 and 2.0 of a canard missile configuration

Description: Report presenting wind-tunnel testing at Mach numbers of 1.5 and 2.0 to investigate the force, moment, and control characteristics of a canard missile configuration and its components in pitch and sideslip. The missile had small all-movable horizontal control surfaces at the nose and a cruciform wing at the rear, all of trapezoidal plan form. Trailing-edge flaps on the vertical fins were provided to supply directional control.
Date: May 11, 1951
Creator: Spahr, J. Richard & Robinson, Robert A.
Partner: UNT Libraries Government Documents Department

Calculated Performance of Nuclear Turbojet Powered Airplane at Flight Mach Number of 0.9

Description: "An analysis was made at flight Mach number of 0.9 to estimate performance of nuclear-energy-powered turbojet engine and optimum engine operating conditions and to determine gross weight and load-carrying capacity of airplane powered by such an engine. The size of airplane required to carry disposable load of 20,000 pounds was found to vary from approximately 300,000 to 900,000 pounds depending on assumptions. For a reactor tube-wall mean temperature of 2500 degrees R, turbine-inlet temperature of 2000 degrees R, reactor-free-flow-area ratio of 0.33, reactor-shielding-material specific gravity of 6.0, shielding thickness of 3.0 feet, and altitude of 30,000 feet, the airplane gross weight required to carry a 20,000 payload is 545,000 pounds" (p. 1).
Date: May 11, 1950
Creator: Doyle, Ronald B.
Partner: UNT Libraries Government Documents Department

Preliminary Results from Free-Jet Tests of a 48-Inch-Diameter Ram-Jet Combustor with an Annular-Piloted Baffle-Type Flameholder

Description: A ram-jet engine with an experimental 48-inch-diameter combustor was investigated in a free-jet facility. The combustor design comprised a large-volume annular pilot region and an array of sloping baffle- or gutter-type flameholders. The combustor was intended to operate at a fuel-air ratio of about 0.037. To promote combustion efficiency at such low fuel-air ratios, a divided-flow system was employed which bypassed a portion of the engine air around the combustion region. Three combustor lengths, three lengths of the shroud which separated the bypass air from the burning stream, and four fuel-distribution systems were investigated over a range of fuel-air ratios from 0.025 to 0.055 and a range of engine air flows from 40 to 110 pounds per second (combustor-outlet total pressures from 500 t o 1800 lb/sq ft abs). The highest efficiencies were obtained with a combustor length of 78 inches and a shroud length of 6 inches. At the lowest air flow, with combustor pressures of about 700 pounds per square foot absolute, a maximum efficiency of about 93 percent was obtained. The efficiency increased with combustor length, a typical increase being from 88 to 95 percent as the length increased from 60 to 96 inches. The length of the shroud separating the bypass air from the burning stream affected not only the efficiency level, but also the fuel-air ratio at which the maximum efficiency occurred. In general, a longer shroud caused the maximum efficiency to occur at lower f'uel-air ratios. Highest efficiencies usually resulted from the use of a fuel-injection system giving a uniform fuel profile. The efficiency at low fuel-air ratios could be considerably improved by the use of a radially nonuniform fuel profile which concentrated the fuel towards the outermost portion of the burning stream The total-pressure ratio across the combustor was about 0.86 at the ...
Date: May 11, 1955
Creator: Rayle, W. D.; Smith, I. D. & Wentworth, C. B.
Partner: UNT Libraries Government Documents Department