Self-noise prediction of a sharp-edged strut using a quasi-periodic CFD-BEM technique

The self-noise generated by a sharp-edged strut immersed in low Mach number flow is predicted using a hybrid computational fluid dynamics (CFD) - boundary element method (BEM) technique. The fluctuating flow field is obtained using an incompressible CFD solver. A high-order reconstruction scheme is used to extract acoustic sources based on Lighthill’s analogy from the flow field data. Acoustic waves generated by these flow noise sources propagate to and are scattered by the trailing edge of the strut. A BEM model of the sharp-edged strut, based on the Burton-Miller formulation, is used to predict the scattered sound pressure. A quasi-periodic technique is implemented in the BEM model so that the sound generated by the entire span of the strut can be predicted by modelling only a small spanwise segment. The results from the hybrid CFD-BEM technique are presented for turbulent flow past a sharp-edged strut, with Reynolds number based on chord Rec=2.0 10 5 and Mach number M=0.044. The computed aerodynamic and acoustic results are compared with experimental data obtained using the anechoic wind tunnel at the University of Adelaide.

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