Finite elements with nonreflecting boundary conditions formulated by the Helmholtz integral equation

In the proposed approach, an acoustic domain is split into two parts by an arbitrary artificial boundary. The surrounding medium around the vibrating surface is discretized with finite elements up to the artificial boundary. The constraint equation specified on the artificial boundary is formulated with the Helmholtz integral equation straightforwardly, in which the source surface coincides with the vibrating surface discretized with boundary ele ments. To ensure the uniqueness of the numerical solution, the composite He lmholtz integral equation proposed by Burton and Miller was adopted. Due to the avoidance of singularity problems inherent in the boundary element for mulation, this method is very efficient and easy to implement in an isopara metric element environment. It should be noted that the present method also can be applied to thin-body problems by using quarter-point elements.