No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 110-112). Also available via the Internet.

No description available.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1997. / Vita. Abstract. Includes bibliographical references (leaves 127-130). Also available via the Internet.

No description available.

High-response pressure measurements of a high-speed, 10- stage, axial-flow compressor operating in rotating stall are analyzed. Procedures used to digitize analog voltages and calibrate pressure transducers are presented. From total and static pressures measured at the exit of the test compressor, stall cell Mach number distributions are calculated and used to study the effects of discharge throttle levels and variable vane changes on the 10th-stage rotating stall cells. Results indicate that significant transition zones exist between the reverse flow and peak Mach number of the stall cell cycle. Since the axial Mach numbers of the stall cell cycle are constantly changing, the amount of leading and trailing edge transition zones and fully unstalled flow zones are not easily defined. A method is devised to approximate the different flow zone ranges and correlate them to in-stall pressure characteristic behavior of the 10th stage of the test compressor. Changes in the time-averaged pressure characteristics are found to correlate with changes in the rotating stall flow zones. A lower pressure coefficient appears to correspond to an increase in the ratio of trailing to leading edge transition zone size and the average transition zone size. Results also suggest that recovery hysteresis in the test compressor is characterized by reverse flow in the rotating stall cell. / Master of Science

A low-speed single-stage axial-flow compressor rig was configured for tests with variable-length upstream casing struts. Two axial strut lengths were tested for their effect on the inlet flow field and stalling characteristics of the compressor under clean and distorted inlet conditions. Data were obtained from one stationary and six blade-mounted high-response pressure transducers, and from a circumferentially- traversed directional probe. The distorted inlet flow field was changed significantly by the longer struts, which effectively sectored the inlet. Deep stall was not observed for this configuration. Rather, the stalling characteristic was changed to what is termed progressive rotating stall, in which six stable stall cells and significant increases in static pressure rise were noted. A new technique for determining the number of rotating stall cells from the frequency content of stationary and rotating reference frame signals is presented. Blade pressure response as a function of aerodynamic loading is detailed. / M.S.

no abstract provided by author / Master of Science

A preliminary theoretical and experimental investigation of the effect of velocity diagram parameters on inlet total-pressure distortions through a single-stage subsonic axial-flow compressor for incompressible flow has been conducted. The wake of 1/4-inch diameter rod, measured both upstream and downstream of a rotor, has been compared for various velocity diagrams. The measured downstream wake was also compared with the downstream wake estimated by using a derived equation subject to the assumption that (a) the undistorted and distorted flows enter the rotor with the same absolute direction, (b) the static pressures of the undistorted and distorted flows are equal at the inlet and also at the exit of the rotor, (c) the increase of blade angle of attack in the distorted flow is not sufficient to cause blade stall, and (d) the distorted flow is turned in the rotor passage to the same exit direction, relative to the rotor, as the undistorted flow.> / Master of Science

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Dr. Lakshmi N. Sankar; Committee Member: Dr. Alex Stein; Committee Member: Dr. J.V. R. Prasad; Committee Member: Dr. Richard Gaeta; Committee Member: Dr. Suresh Menon. Part of the SMARTech Electronic Thesis and Dissertation Collection.