Engineering Commons^™

Flow Excited Acoustic Resonance In A Deep Cavity: An Analytical Model, William W. Durgin, Hans R. Graf

Office of the Provost Scholarship

Flow past the opening of a deep cavity can excite and sustain longitudinal acoustic modes resulting in large pressure fluctuations and loud tone generation. An analytic model of the interaction of the free stream with the acoustic flow field using concentrated vortices in the shear layer is proposed. The model includes a computation of the power transferred by the traveling vortices to the acoustic oscillation in the cavity. Experimentally measured values for the vortex convection velocity and phase are used to enable calculation of the ensuing oscillation amplititude and frequency ratio. The radiated acoustic power is calculated using the model …

Spaceflight Payload Design, Flight Experience G-408, William W. Durgin, Fred J. Looft, Albert Sacco, Jr., Robert Thompson, Anthony G. Dixon, Dino Roberti, Robert Labonte, Larry Moschini

Office of the Provost Scholarship

Worcester Polytechnic Institute's first payload of spaceflight experiments flew aboard Columbia, STS-40, during June of 1991 and culminated eight years of work by students and faculty. The Get Away Special (GAS) payload was installed on the GAS bridge assembly at the aft end of the cargo bay behind the Spacelab Life Sciences (SLS-l) laboratory. The experiments were turned on by astronaut signal after reaching orbit and then functioned for 72 hours. Environmental and experimental measurements were recorded on three cassette tapes which, together with zeolite crystals grown on orbit, formed the basis of subsequent analyses.

The experiments were developed over …