Simulation of Broadband Noise Behind a Backward Facing Step

The internal flow and the sound field over a backward-facing step in the transitional regime (ReD = 6000) was predicted based on direct numerical simulations (DNS) for the flow field. The flow predictions were carried out with the help of a finite-volume NavierStokes solver equipped with a co-visualization facility which allows one to investigate the flow dynamics at high temporal resolution. The sound field was investigated with the Finite Element method using the acoustic analogy approach. To analyse the broadband character of the sound radiation a special absorbing layer (Perfect Matched Layer) technique was implemented in the time domain to achieve optimal free radiation conditions. The results show clearly the broadband characteristics of the radiated acoustic field.

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