An air jet emanating from a rectangular conduit with exit plane dimensions 7.62 cm x 1.27 cm (aspect ratio 6:1) is forced using four piezoelectric actuators mounted along the long sides of the jet opening. Excitation is effected via amplitude modulation of the resonant carrier waveform. Although the flow is not normally receptive to excitation at the actuator resonance frequency, if the excitation amplitude is high enough, spreading of the forced segments of the jet shear layer can lead to a significant deflection of the jet column. When the amplitude modulated excitation is high enough, the input waveform is effectively demodulated by a nonlinear process related to the formation and coalescence of nominally spanwise vortices. The resulting effect is the spatial amplification and attenuation of the modulation and resonant wavetrains, respectively. The choice of different spatial/temporal wavetrains can result in the excitation of spanwise and streamwise instabilities of the jet column.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/278089 |
| Date | January 1992 |
| Creators | Green, Stephen Marcus, 1957- |
| Contributors | Glezer, Ari |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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