Response of Turbulent Boundary Layer to Sound Waves Propagating in Main Flow.

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The subject of this research is on the acoustic streaming generated in a boundary layer adjacent to a solid wall resulting when a acoustic wave propagates in a main flow along the wall. For the first approach, the streaming by an acoustic standing wave in a duct with and without mean flow is confirmed by visualizations by means of laser-beam-sweep method and measurements of oscillatory flow velocity by hot wire anemometry. And then, the thermoacoustic streaming effect in Hartmann-Sprenger tube generated by finite amplitude wave motions and the streaming by strong whistling generated in Ranque-Hilsch tubes are discussed. The results obtained by this investigation are as follows; 1. Visualized patterns of the streaming by the standing waves in a rectangular duct are different from the results obtained by two-dimensional analysis under Lord Rayliegh. 2. The thermoacoustic effects in Hartmann-Sprenger tubes are presented by wall temperature distributions corresponding to oscillation modes. 3. It was theoretically predicted that the acoustic streaming resulting from strong whistling generated in swirling flow in Ranque-Hilsch tubes changes tangential velocity destributions, resulting in total temperarure separation in radial direction.