CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM Meshing & Mesh Conversion (https://www.cfd-online.com/Forums/openfoam-meshing/)
-   -   [Technical] Tet elements vs Hex elements (https://www.cfd-online.com/Forums/openfoam-meshing/61939-tet-elements-vs-hex-elements.html)

Pei-Ying Hsieh (Hsieh) March 4, 2005 14:15

Tet elements vs Hex elements
 
Hi,

I understand that hex elements are superior than the tet elements, but, can anyone give me a brief summary of the differences?

For complex geometries, most commercial codes use tet meshes. How much accuracy suffers when using tet meshes?

Thanks!

Pei

Henry Weller (Henry) March 6, 2005 11:41

Yes hex and polyhedral cells
 
Yes hex and polyhedral cells are generally superior to tet cells in finite-volume and the difference in both accuracy and convergence behaviour can be large. However, it also depends on the quality of the hex and tet cells and many of the problems with tet meshes stem from the poor quality of some tets produced by many automatic tet mesh generators. In order to really appreciate the difference it might be a good idea for you to try both for your problems. For VOF calculations I would expect the solution on hex/poly cell meshes to be dramatically better.

I do not agree with your statement that "most commercial codes use tet meshes", they certainly support tet meshes but do not use them exclusively and most finite-volume code developers and suppliers recommend the use of hex meshes over tet-meshes if at all possible.

giuseppe March 26, 2005 04:11

HI, I work also with finite e
 
HI,
I work also with finite element commercial code: generally the use of tet is based on the existence of automatic tet mesh generation codes.
It is very easy to generate a tet mesh from igs or stp cad complex model !
To increase the accuracy it is suitable to use tet10 elements.


Giuseppe

hsieh March 26, 2005 07:58

Hi, Giuseppe, Does OpenFOAM
 
Hi, Giuseppe,

Does OpenFOAM supports tet10 element?

Pei

mattijs March 28, 2005 07:43

No. The finiteElement solver h
 
No. The finiteElement solver has only linear tet elements.

Mattijs


All times are GMT -4. The time now is 17:38.