DYNAMIC UNSTRUCTURED GRID METHOD WITH APPLICATIONS TO 3D UNSTEADY FLOWS INVOLVING MOVING BOUNDARIES
非结构动网格在三维可动边界问题中的应用

Spring analogy method for dynamic unstructured grids is studied. The stiffness of the springs in the modified vertex spring analogy is analyzed. Improvements considering torsional spring effect and boundary effect are developed to standard method. Application of the improved spring analogy method to rotating airfoil grids shows that the new method greatly improves the deforming ability and the quality of the mesh. This dynamic grid method coupled with 3-D ALE Euler solver is then applied to simulate unsteady transonic flow about an oscillating rigid rectangular wing. Computational results are in good agreement with experimental data and that of other literature. To demonstrate the capability in solving interaction problems of multiple rigid body and fluid, the whole methodology coupled with rigid body dynamics equations is used to simulate propagating shock and double cube interaction, time-dependent flow structures are obtained. It can be concluded from the research that the improved spring analogy method coupled with the unsteady finite volume solver developed in this paper, is an effective way to study fluid and structure interaction problems with small boundary displacement.