Application of a novel triangular element to two-dimensional underwater acoustic scattering problems

To improve the performance of the standard finite element (FE) method in acoustic simulation, a novel triangular element with continuous nodal acoustic pressure gradient (FEM-T3-CNG) is presented to solve the two-dimensional underwater acoustic scattering problems. In this FEM-T3-CNG model, the local approximation (LA) is represented by using the moving least-squares (MLS) scheme and the standard FE shape functions are employed to satisfy the partition of unity (PU) concept. In order to possess the important delta Kronecker property, the constrained orthonormalized MLS (CO-MLS) is utilized to construct the hybrid nodal shape functions. Incorporating the present FEM-T3-CNG element with the proper non-reflecting boundary condition, the two-dimensional underwater acoustic scattering problems in infinite domain could be solved ultimately. The numerical results show that the present FEM-T3-CNG element behaves much better than the standard FEM-T3 element in terms of computation accuracy and can be regarded as a good alternative approach in exterior acoustic computation.