Tet and prism Grid
 

Hi

Could any one please tell me what the differences between a tetrahedral and prismatic grid is ??

Kind Regards

Newbi

Re: Tet and prism Grid
 

1) A tet is a volume element with 4 nodes. 2) A prism element has 6 nodes. 3) You normally use a tet mesh when you have a complicated geometry and use an automatic volume mesher like ICEM Tetra or Hypermesh or ... 4) But there are problems in the near wall region when you only use tets there. Often you want to have elements there with faces perpendicular to the wall or near wall flow direction. One way to solve this is the following. Starting from a triangulated surface you can get such elements simply by extruding that triangles into the inside of the volume. That gives you prismatic elements. You can repeat this step some times to get more then one so called prism layer. Then, applying the automatic mesher to the subvolume described by the inner triangulated surface of the prism layer you can fill the remaining volume with tets