Delaunay background grid,edge spring grid and linear spring grid are used to study computational domain grid movement on non-structural grid and structure grid for non-streamlined bridge section.It shows that the methods are effective as grid deformation within a normal vibration amplitude of the bridge section.Delaunay grid background method consumes the least time and the linear spring grid method obtains the highest quality.It also shows that with large amplitudes,structural grid is invalid easily and linear spring grid method ensures effectively.

An iterative method for unstructured dynamic-grid using springs based on LU-SGS (lower-upper symmetric Gauss-Seidel) is presented to reduce time of iterative in dynamic discontinuities simulation. Dynamic grid iterative time is as much as time of field itemtive as shock and flex-wall are numerical fitting by time-dependent Euler equations, because dynamic boundary is moving and whole unstructured grids are updated in every step of field iterative. A sparse matrix mapping grid topology based on spring strategy is presented. LU-SGS strategy is used in numerical simulation and dynamic grid is managed in order to solve the time choke point. Numerical results show that LU-SGS iterative method can be used to dynamic discontinuities fitting by implicit scheme. The presented method decreases more than 20% iterative time than classical SOR method.