A coupled weak-form meshfree method for underwater noise prediction

A meshfree weak-form method based on combining a radial point interpolation method (RPIM) and modified Dirichlet-to-Neumann (MDtN) boundary condition is proposed for use in analyzing underwater acoustic radiation. To apply a meshfree weak-form method to exterior acoustic radiation prediction, an unbounded problem domain is truncated by an artificial boundary to yield a finite computational domain. To improve the interpolation accuracy, RPIM is used to form an acoustic shape function without use of a mesh or connectivity of nodes to implement field variable interpolations. An MDtN boundary condition is imposed on the artificial boundary to guarantee a unique solution. The factors affecting the performance of the devised method are investigated, and numerical examples are used to test its performance. Simulations indicate that the method can produce more accurate results and converge faster and more efficiently, and is less sensitive to the acoustic wavenumber than the finite element scheme. Therefore, this proposed method is competitive at predicting underwater acoustic radiation.