 |
 |
 |
 |
 |
 |
 |
Today’s sophisticated analysis environment requires geometry integrated mesh generation and post-processing tools. ANSYS ICEM CFD maintains a close relationship with geometry during mesh generation, smoothing, mesh editing, and post-processing. ANSYS ICEM CFD provides sophisticated geometry acquisition, mesh generation, mesh editing, a wide variety of solver outputs and post-processing.
The ANSYS ICEM CFD toolbox is large and supports a wide variety of processes. Here we will overview the general process as well as provide some insight into the processes of specific meshers.
In ANSYS ICEM CFD, the general process starts with importing or creating geometry, possibly repairing geometry, then setting up global and local meshing parameters. The user selects the appropriate grid generation module to create the computational grid. The boundary conditions can also be attached to entities or parts/components. The mesh, boundary conditions and topology information then can be translated into over 100 flow solvers and structural analysis codes. ANSYS ICEM CFD offers a wide range of mesh smoothing, boundary condition editing and mesh visualization tools for both structured and unstructured meshes. Finally, the results are visualized and analyzed with a post-processing tool. It is possible to do things out of order, skip steps, etc. but this is a typical workflow
ANSYS ICEM CFD takes a time saving approach to pre-processing by allowing engineers to use the original 3D CAD geometry instead of building separate analysis models. ANSYS ICEM CFD supports geometry import from a variety of sources. ANSYS ICEM CFD can import faceted geometry such as STL, VRML, Mesh formats, point cloud data. It can import generic geometry such as Step/IGES, ACIS, DWG/DXF, Rhino3D, Parasolid, IDI, GEMs, etc. It can import CAD directly from major packages like Pro/E or UG. It can also be used within the major CAD packages to setup for meshing and then write out an ICEM CFD geometry file. The ANSYS Workbench platform readers are also available thru ANSYS ICEM CFD.
ICEM CFD takes a new approach to pre-processing by allowing engineers to use the original 3D CAD geometry instead of building separate analysis models. ICEM CFD’s grid generation modules utilize multiple ways of integrating CAD geometry to analysis.
If you do not have geometry, you can create it with our ANSYS ICEM CFD or ANSYS DesignModeler tools. The ANSYS DesignModeler tools are more advanced and include options for applying or removing fillets, Booleans, etc. The ANSYS ICEM CFD Geometry tools are surface based, which can be advantageous in certain situations, ANSYS ICEM CFD also has excellent faceted repair tools.
The geometry database in ANSYS ICEM CFD can combine geometries acquired or created. For instance users can combine STL data with geometry acquired from direct CAD interfaces and with geometry created internal to ANSYS ICEM CFD.
The geometry tab also has tools for geometry repair, feature extraction and breaking the geometry into various components (parts), which are useful later for applying boundary conditions.
Mesh Parameters can be applied globally and to geometry entities to control the mesh. Most of the controls are generic and apply across a variety of meshers. For FEA applications, connectors can be created at the geometry level or after meshing.
When choosing a mesh method, it is important to understand that some are patch conforming and some are patch independent. The patch conforming methods start from the surface patches (or loops) and generate a surface mesh. It is also possible to generate a surface mesh with one of the patch independent surface meshing methods (octree or cartesian based) that can then be followed by bottom up fill methods.
The surface mesh generation would then be followed by a bottom up method to create Hexa dominant, Tetra or Prism mesh. Note that the prism mesh can be grown bottom up, or inserted (top down) into an existing tetra mesh. Finally, the tetra core could be replaced with a hexa core.
The patch independent methods are independent of the surface patches and this can be a powerful advantage, particularly with poor geometry. The Octree method starts with the volume and fits tetra mesh to the geometry. The Cartesian method is similar, except it fits hexas to the geometry. The hexa blocking method uses a separate “blocking” layer to control the mapped or swept volumes, which are then associated (fit) to the geometry.
It is also possible to import a mesh from Workbench or elsewhere for use with ANSYS ICEM CFD Mesh editing or remeshing.
Once the mesh is created or imported, you can use the ANSYS ICEM CFD Mesh diagnostics and Mesh editing tools. ANSYS ICEM CFD Mesh editing has the distinct advantage of maintaining the relationship between the mesh and the geometry. This means that the automatic and interactive mesh editing maintains the features of the geometry. These mesh editing tools can also be used to hybridize or merge meshes to produce more advanced models.
Outputting to CFD is typically a simple process of selecting the solver from our long list of supported formats. Then applying basic part/component based boundary conditions. Some solvers also have parameter settings. Then output a file in the appropriate format, transfer it to the solver and run the solver.
The FEA setup is generally more advanced and may involve creating or importing material properties, setting up element properties, constraints and loads. Some FEA solvers, support solver properties, attributes, or load cases. The user can then output the model in the appropriate format. The solver can be run separately, or in batch from the ANSYS ICEM CFD environment.
After running the solver, the user may want to post-process the results. There are many options on the market including ours, those created by the solver vendors, or third party post-processing tools.
The user may also export a deformed mesh from the post processor or solver and send that back to ANSYS ICEM CFD.
