Computation of uniform mean flow acoustic scattering by single layer regularized meshless method

Abstract

The simulation of the acoustic fields propagating in moving flows and the interaction of such fields with the mean flow itself is of importance in aviation acoustic prediction. Volume methods are preferred in this area. Boundary integral method is also concerned because of its own advantages. The transformation space is usually adopted in solving the convective Helmholtz Equation, physical space is also preferred for the convenient boundary condition implementation and combination with other methods. In this paper, the Convective Helmholtz Equation is solved by the Single layer Regularized Meshless Method (SRMM) in the physical space. The SRMM has been proposed by the author for the Laplace equation and Helmholtz Equation. SRMM has similar idea with the Equivalent Source Method (ESM), which represents the fields by the monopoles. But the source points overlap physical points. It overcomes the difficulty of the source points location choice, but the singularity arises. The subtraction and adding-back technique is adopted to get the amplitude of the singularity. The Dual-Surface Method is adopted to avoid irregular frequencies.