A Meshfree Radial Point Interpolation Coupled with Infinite Acoustic Wave Envelope Element Method for Computing Acoustic Fields

To take advantage of the meshfree method in computational accuracy, the meshfree radial point interpolation method (RPIM) is introduced to compute acoustic fields in infinite domain. A hybrid meshfree-infinite acoustic wave envelope element method is proposed for acoustic radiation prediction. To improve the accuracy, soften the system stiffness compared to the "overly-stiff" finite element method, and properly model the amplitude decay of the outgoing travelling wave, the RPIM in near field is combined with a variable-order infinite acoustic wave envelope element (WEE) in far field to establish the discretized system equations. The coupling of the PRIM and WEE is achieved by interface elements to maintain the continuity and compatibility on the interface between the two domains, where the RPIM and WEE methods are applied. The suitable shape parameters of radial basis functions and the size of the influence domain, which influence the performance of this method, are determined by numerical experiments. From the numerical results, the method not only can provide data with high accuracy but also has a faster convergence speed than the conventional method of the finite element method (FEM) combined with WEE. The method can take full advantage of both the RPIM and WEE methods. The experimental results show that the method is very flexible for acoustic radiation prediction in the infinite domain.