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Some Effects of Rapid Inlet Pressure Oscillation on the Operation of a Turbojet Engine

Description: A program was conducted in an altitude facility at the NACA Lewis laboratory to investigate the effects of rapid inlet pressure oscillations on the operation of a current turbo jet engine. These pressure oscillations were approximately sinusoidal in form and were generated to cover a frequency range of 2 to 75 cycles per second and an amplitude range of 10 to 70 percent of the free-stream total pressure. As the oscillation progressed through the compressor, the amplitude was attenuated considerably and a relatively large phase shift (lag) occurred. Engine stall limits obtained during pressure oscillations differed from quasi-steady-state stall limits as defined by over-all compressor pressure ratio.
Date: January 7, 1958
Creator: Russey, Robert E. & Lubick, Robert J.
Partner: UNT Libraries Government Documents Department

Steady-state and surge characteristics of a compressor equipped with variable inlet guide vanes operating in a turbojet engine

Description: Report presenting an investigation of a turbojet engine with variable inlet guide vanes in an altitude test facility to determine the steady-state compressor performance and surge characteristics. Compressor surge pressure ratios were found to be unaffected by changes in flight condition for either position of the inlet guide vanes. Decreasing the inlet Reynolds number was found to reduce the corrected fuel flow required for compressor surge.
Date: June 20, 1955
Creator: Wallner, Lewis E. & Lubick, Robert J.
Partner: UNT Libraries Government Documents Department

Preliminary Transient Performance Data on the J73 Turbojet Engine 2 - Altitude, 35,000 Feet

Description: A program was undertaken to determine the J73 turbojet engine compressor stall and surge characteristics and combustor blow-out limits encountered during transient engine operation. Data were obtained in the form of oscillograph traces showing the time history of several engine performance parameters with changes in engine fuel flow. The data presented in this report are for step changes in fuel flow at an altitude of 35,000 feet, at flight Mach numbers of 0.3, 0.8, and 1.2, and at several engine-inlet temperatures,.
Date: July 16, 1953
Creator: Lubick, Robert J. & Sobolewski, Adam E.
Partner: UNT Libraries Government Documents Department

Altitude operational characteristics of prototype J40-WE-8 turbojet engine

Description: From Introduction: "The altitude performance characteristics of the prototype J40-WE-8 turbojet engine were determined in the NACA Lewis altitude wind tunnel. The altitude operational characteristics of the engine are presented herein. The results of a brief study of the effect of the two different grades of fuel (MIL-F-5624A grades JP-3 and JP-4) on steady-state engine performance at an altitude of 45,000 feet and a flight Mach number of 0.20 are also given."
Date: August 14, 1953
Creator: Sobolewski, Adam E. & Lubick, Robert J.
Partner: UNT Libraries Government Documents Department

Surge-inception study in a two-spool turbojet engine

Description: Report discussing a study of compressor behavior leading to surge involving extensive instrumentation to obtain information about pressure at various points in the compressor. Information about where and under what conditions rotating stall occurred is given special attention.
Date: 1956
Creator: Wallner, Lewis E.; Lubick, Robert J. & Saari, Martin J.
Partner: UNT Libraries Government Documents Department

Stall and flame-out resulting from firing of armament

Description: Report presenting an analysis of the causes of compressor stall and flame-out when armament is fired during flight at high altitudes. Experimental data are also presented. The increase in compressor-inlet temperature during armament firing was found to be the most important single factor affecting engine performance.
Date: August 5, 1955
Creator: Childs, J. Howard; Kochendorfer, Fred D.; Lubick, Robert J. & Friedman, Robert
Partner: UNT Libraries Government Documents Department

Preliminary Data on the Effects of Inlet Pressure Distortions on the J57-P-1 Turbojet Engine

Description: "An investigation to determine the steady-state and surge characteristics of the J57-P-1 two-spool turbojet engine with various inlet air-flow distortions was conducted in the altitude wind tunnel at the NACA Lewis laboratory. Along with a uniform inlet total-pressure distribution, one circumferential and three radial pressure distortions were investigated. Data were obtained over a complete range of compressor speeds both with and without intercompressor air bleed at a flight Mach number of 0.8 and at altitudes of 35,000 and 50,000 feet" (p. 1).
Date: December 3, 1954
Creator: Wallner, Lewis E.; Lubick, Robert J. & Einstein, Thomas H.
Partner: UNT Libraries Government Documents Department

Surge-Inception Study in a Two-Spool Turbojet Engine, Revised

Description: "A two-spool turbojet engine was operated in the Lewis altitude wind tunnel to study the inception of compressor surge. In addition to the usual steady-state pressure and temperature measurements, the compressors were extensively instrumented with fast-response interstage pressure transducers. Thus it was possible to obtain maps for both compressors, pressure oscillations during rotating stall, effects of stall on efficiency, and stage-loading curves" (p. 1).
Date: November 12, 1957
Creator: Wallner, Lewis E.; Lubick, Robert J. & Saari, Martin J.
Partner: UNT Libraries Government Documents Department

Effect of inlet-duct length in uniform-flow field on turbojet-engine operation

Description: Report presenting a high-pressure-ratio axial-flow turbojet engine in the altitude wind tunnel to determine the effect of inlet-duct length on engine operation. Data were obtained with a short bellmouth inlet and a 20-foot duct section of uniform diameter between the inlet and compressor. Results regarding the steady-state characteristics, acceleration characteristics, compressor stall limits, and surge characteristics are provided.
Date: April 11, 1956
Creator: Lubick, Robert J.; Chelko, Louis J. & Wallner, Lewis E.
Partner: UNT Libraries Government Documents Department

Evaluation of an automatic inlet-pressure control valve for study of transient engine performance characteristics

Description: Report presenting an evaluation of data obtained with an automatic constant inlet-pressure control valve designed to facilitate the study of transient engine performance characteristics in the altitude wind tunnel. The engine characteristics obtained by use of the pressure valve were compared with those obtained with a bellmouth inlet operating in simulated free-stream conditions.
Date: April 6, 1956
Creator: Wallner, Lewis E.; Lubick, Robert J. & Bloomer, Harry E.
Partner: UNT Libraries Government Documents Department

Inlet-air distortion effects on stall, surge, and acceleration margin of a turbojet engine equipped with variable compressor inlet guide vanes

Description: Report presenting an investigation of a turbojet engine in an altitude test chamber to determine the effects of a wide range of uneven inlet-air pressure distributions on transient characteristics and stall phenomenon. Circumferential, radial, and mixed pressure variations were run at three simulated altitudes and a simulated Mach number of 0.80. Results regarding the compressor characteristics, compressor stage performance, and acceleration margin are provided.
Date: October 4, 1955
Creator: Harry, David P., III & Lubick, Robert J.
Partner: UNT Libraries Government Documents Department

Preliminary investigation of the effects of altitude and inlet-pressure distortions on steady-state and surge fuel flow of the J57-P-1 turbojet engine

Description: Report presenting an investigation to determine the effects of altitude and inlet-pressure distortions on the steady-state and surge characteristics of the J57-P-1 two-spool turbojet engine in the altitude wind tunnel. Steady-state performance and surge fuel flows were obtained with a uniform inlet distribution at a range of altitudes at flight Mach number 0.8.
Date: January 21, 1955
Creator: Lubick, Robert J.; Meyer, William R. & Wallner, Lewis E.
Partner: UNT Libraries Government Documents Department