NUMERICAL SIMULATION OF UNSTEADY VISCOUS FLOWS USING A GRID DEFORMATION TECHNIQUE ON HYBRID UNSTRUCTURED MESHES

비정렬 혼합 격자계에서 격자 변형 기법을 이용한 비정상 점성 유동 수치 모사

In the present study, a grid deformation technique has been incorporated into the unsteady compressible and incompressible viscous flow solvers on unstructured hybrid meshes. An algebraic method based on the basis decomposition of normal edge vector was used for the deformation of viscous elements, and a ball-vertex spring analogy was adopted for inviscid elements among several spring analogy methods due to its robustness. The present method was validated by comparing the results obtained from the grid deformation and the rigid motion of entire grids. Fish swimming motion of an NACA0012 airfoil and flapping wing motion of a generic fighter were simulated to demonstrate the robustness of the present grid deformation technique.