PREDICTION OF FLOW-INDUCED NOISE USING THE EXPANSION ABOUT INCOMPRESSIBLE FLOW APPROACH

Abstract. In the present paper an Expansion about Incompressible Flow approach, as suggested by Shen and Sørensen1, will be used and discussed for the simulation of flow-induced sound at low Mach numbers. The method consists of two parts: First solving for the incompressible, viscous flow field, and second computing the fluctuating acoustic field. As a result of this splitting approach, one can choose optimized numerical methods and grid sizes for each of the two parts. In the current contribution an explicit finite difference scheme is employed to solve the nonlinear acoustic equations, and the propagation and scattering of the sound are computed simultaneously. The acoustic results are presented for the sound generated by a circular cylinder in a flow at the Reynolds number of 150. In particular, the influence of the discretization parameters and the implementation of numerical filters are discussed and the accuracy of this hybrid method is compared to other approaches.