A Quick Overview of ICEM
What is ICEM?
ICEM is a software developped
by ICEM CFD engineering which provides sophisticated geometry tools for
CAO, mesh generation, post-processing and mesh optimization tools. It is
used for engineering applications such as computational fluid dynamics
and structural analysis. The grid generation tools offer the capability
to parametrically create grids from geometry in multiblock structured,
unstructured hexahedral, tetrahedral, hybrid grids consisting of hexahedral,
tetrahedral, pyramidal and prismatic cells; and cartesian grid formats
boundary conditions. Over 100 flow solver and structural analysis translators are provided to produce an input file containing mesh and boundary conditions. ICEM CFD also offers tools for
post-processing and mesh optimization.
ICEM is an "open" mesher, ie it is able to receive geometries from CAO software like Autocad,Nastran, etc.... Moreover it can generate meshes from these geometries to read them with Computanional Fluid Dynamics codes like Fluent, StarCD or with Computational Solid Dynamics like Nastran, Patran etc....
In the industry, ICEM is used by some huge companies such as Boeing, Toyota or in some NASA centers.
How to use it?
Even if it is quite difficult to create a geometry and to generate a mesh for a first use of ICEM, we give here a quick overview about how to use ICEM. It can be divided into 4 steps.
1st step: the first consists in creating the geometry of the problem with the patr of ICEM called DDN. The window used by ICEM looks like that:
It is a real CAO software,
it is possible to create any geometry from points, curves, surfaces etc...
A particularity of ICEM is that it uses projections to generate the mesh, so the mesher will only accept what it calls B-Spline. Then all the curves needs to be converted to B-Spline curves.
A important part is to create a domain point to indicate which volume (or surface) will be meshed.
2nd step: after generating the geometry, boundary regions needs to be created. For this ICEM use DDN->Tetin which allow to create some families of boundaries (a family of Inlet, a family of Fluid etc...) and to locate them on our geometry.
3rd step: in this third step the mesh is generated. It is maybe the most difficult part. First it is possible to choose between several type of mesh: Hexa, Prism, Tetra etc...
At the beginning, our geometry is located inside a cube (or a square in 2D). And we have to cut it in different blocks in order to fit as much as possible the geometry.
After that the next step is to project the different curve of our geometry on the different edges of of these blocks .
Finally, we have the mesh.
4th step: the last
step is to choose the solver, to indicate the boundary conditions, and
to save our mesh.
Here are some applications
we found on the website of ICEM CFD Engineering (http://www.icemcfd.com):
Space Shuttle Orbiter (Tetrahedral
grid with prism layers form surfaces).
Fighter Antenna Pod (Multi-Block structured grid).
Tetrahedral Volume Mesh for Climate Control Model (CFD model of interior cabin).