Analysis of diffraction-radiation problem by the meshless method

In the present paper, the concept of the meshless element free Galerkin method, in which only nodal data are required to make a numerical analysis model, is applied to the linear wave diffraction and radiation problems. The meshless method has advantages of no mesh and no element connectivity, so the preprocessing task for mesh generation may be reduced. The numerical formulation and the implementation of the meshless method for calculating wave field solutions of diffraction and radiation problems are presented. Then numerical analysis is carried out for a floating breakwater to prove the validity of the meshless based numerical model. Comparisons with the results from the previous experiment and other solution method show that the present model gives fairly good results. Several numerical examples are performed to examine the accuracy of the developed numerical model. Numerical results show that the accuracy of the solution is sensitive to the size of influence domain and the density of node distribution. It is found that large influence domain may generate phase errors for the case of short incident waves. However the suitable criteria unaffected by the size of influence domain in order to keep the accuracy of solution may exist. From the numerical results, the criteria related to the nodal distance and wave number is proposed. By using the present numerical model the performance of a moored floating breakwater is investigated under various design parameters.