Abstract: A compressor or pump is connected to a discharge plenum. The plenum includes a movable wall whose motion varies the volume of the plenum. The wall is connected to passive elements forming a spring-mass-damper system whose characteristics are selected to damp pressure fluctuations in the plenum which would give rise to pumping system instabilities. In another aspect of the invention, a compressor is connected to a discharge plenum which in turn is connected to an exit throttle. The throttle includes a movable portion whose motion varies the throttle area. The movable portion is connected to passive elements forming a spring-mass-damper system selected to damp pressure fluctuations in the plenum. In another embodiment, the plenum communicates with a fixed area throttle and a variable area throttle. The variable area throttle includes a movable portion connected to passive elements selected to damp pressure fluctuations in the plenum.

Abstract: Double-sided, high-frequency response heat flux gauge for use on metal tune blading consists of a metal film (1500A) resistance thermometer sputtered on both sides of a thin (25 .mu.m) polyimide sheet. The temperature difference across the polyimide is a direct measure of the heat flux at low frequencies, while a quasi-one-dimensional analysis is used to infer the high-frequency heat flux from the upper surface history. A new method of calibrating the heat flux gauge utilizes light source applied to a plurality of fluids covering the surface of the gauge, measuring the temporal output of the gauge and utilizing derived calibration formula.

Abstract: Double-sided, high-frequency response heat flux gauge for use on metal turbine blading consists of a metal film (1500A) resistance thermometer sputtered on both sides of a thin (25 .mu.m) polyimide sheet. The temperature difference across the polyimide is a direct measure of the heat flux at low frequencies, while a quasi-ID analysis is used to infer the high-frequency heat flux from the upper surface history.