文稿说明2021-06学习icem.pptx

Lecture 6 Mesh Preparation Before Output to Solver Introduction to ANSYS ICEM CFD Mesh Preparation Before Output to Solver Many tools in the Edit Mesh tab Smooth, check errors, coarsen, refine, individual element editing Two important things should always be done before outputting the mesh to the solver Make sure the mesh is error-free by going through the Error and Possible Problem checks Fix any problems Smooth the mesh to an acceptable quality Fix any problems which cannot smooth to the minimum quality These two steps are not necessary with a structured hexa mesh because they are usually handled with the tools in the Blocking tab When fixing errors or low quality problems, there are always two basic choices: If there are few problems, edit the elements directly to fix If there are many problems, inspect the source of the problem, such as a mesh size or geometry problem, then fix this and remesh Either choice involves the use of mesh subsets to visualize the problem elements Mesh Checks To diagnose mesh connectivity problems Errors – most likely to cause problems in: Translation to solver Solver mesh input Solution convergence/run Possible Problems – “Unclean surface mesh” Strange configurations of elements, sharp peaks Unwanted holes/gaps May result in incorrect solution Definitions of errors and possible problems found in appendix and help Can check any combination of errors/possible problems Individually select Clicking on Error or Possible Problems headings will select all options in column – selecting again will de-select all Set Defaults will select the most common checks for the current mesh type (2D or 3D) Check Mode Create Subsets – creates a subset of elements for each problem found (will run through all selected checks) Check/Fix Each – offers automatic fixing of some problems (needs user decision after each problem found) Mesh Checks – Check Mode If Create Subsets was selected Will go through all checked criteria without interruption Elements that