Fluid-Structure-Acoustics Interaction of the Flow Past a Thin Flexible Structure

The acoustic field resulting from the interaction of a thin flexible structure with a turbulent flow was investigated both numerically and experimentally. Two different model configurations were considered: in one a flexible plate acted as a moving wall in a turbulent boundary layer, and in the other the flexible plate was located in the wake of a square cylinder. The fully coupled simulation of the fluid—structure—acoustics interaction was based on a partitioned approach employing two different simulation codes: a finite-volume flow solver of second-order accuracy in space and time and a finite-element structural-mechanics and acoustics solver. A code coupling interface was used for the exchange of data between the different discretizations. The experiments were performed in an acoustic wind tunnel employing microphone measurements of the sound pressure level. Detailed flow measurements were carried out using laser Doppler anemometry and three-component hot-wire anemometry. The flow-induced vibration of the flexible structure was measured with a laser-scanning vibrometer. Experimental and numerical results characterizing the flow field, the structural vibration, and the generated sound are presented.

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