tailieunhanh - Applied Computational Fluid Dynamics Techniques - Wiley Episode 2 Part 3

Tham khảo tài liệu 'applied computational fluid dynamics techniques - wiley episode 2 part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | ADAPTIVE MESH REFINEMENT 293 c Figure . Continued 294 APPLIED COMPUTATIONAL FLUID DYNAMICS TECHNIQUES . SHOCK-OBJECT INTERACTION IN TWO DIMENSIONS Figures a - c show a case taken from Baum and Lohner 1992 . They show classic h-refinement for strongly unsteady flows at its best. For this class of problems a new mesh is required every five to seven timesteps strict conservation of mass momentum and energy during refinement is critical and the introduction of dissipation due to information loss during interpolation when remeshing proves disastrous for accuracy. A maximum of six levels of refinement were specified for this case yielding meshes that on average have 300000 triangles and 100 000 points. Figures a and b show the mesh mesh refinement levels and pressures for different times. a b Figure . Shock-object interaction in three dimensions Observe the detail in the physics that is achievable through adaptation. Notice furthermore the small extent of the regions that require refinement as compared to the overall domain. The equivalent uniform mesh run would have required more than two orders of magnitude more elements CPU time and memory pushing the limits of available supercomputers. The ADAPTIVE MESH REFINEMENT 295 a b c Figure . Shock-structure interaction a building definition b surface mesh and pressure c mesh and pressure in .