CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   ANSYS Meshing & Geometry (http://www.cfd-online.com/Forums/ansys-meshing/)
-   -   [Other] Mesh generation (http://www.cfd-online.com/Forums/ansys-meshing/108587-mesh-generation.html)

avsksan October 27, 2012 00:21

Mesh generation
 
Hai,
I am new to CFD can i know which is the best software to create mesh

Far October 27, 2012 01:38

Rule of thumb:

1. Use the mesh generator which is being used by your friends who are available to help you out.

2.Best sotware in market is ICEM (Hexa), but it is difficult to learn and takes alot time in mastering. Its tetra + prism version is very efficient and easy to use.

3. Ansys meshing is new technology and very easy to use.

4. Gambit is very easy to learn and its tetra with boundary layer (in 3d implementing boundary layer often produces error) is very good. Its size functions are awesome and some of them are also implemented in ICEM CFD. So if this product is available in your lab then it is best idea to start with gambit.

5. Gridgen is very good mesher and has technology of hexa, tetra and T-Rex (equalivalent for prisms). It produces very highly quality meshing. It has the capability to produce the hybrid meshes and which is its plus point as compared to ICEM. ICEM can produce the hybrid meshes, but it is cumbersome.

6. T-grid is also very good unstructured mesher, but it requires surface mesh. It is mostly used in automotive industry. Tgrid has advantage of producing very large mesh (more than 40 million) in very short time and use very less computational resources. A desktop with 8 gb RAM and corei7 would be enough for this task.

7. You can use combination of different meshers. For example recently one of my freind used the Gambit and ICEM. They used Gambit for geometry cleaning (also reproduces some dirty parts) and tetra volume mesh. This mesh was saved in .msh format and imported into ICEM. Where with build topoogy underlying goemtry was reproduced and then prism mesh was extruded from the tetra mesh near to wall surface.

8. Some times people also use the ANSA for surface mesh and then either Tgrid or ICEM for volume mesh. Mostly for automotive meshing. ICEM is popular in aerospace, external analysis of automotive, turbo-machinery and any other complex geometry.

If you ask for my preference I would say:

1. For learning purpose start with Gambit or gridgen.

2. For hybrid mesh use Gridgen.

3. For high quality hexa meshes use ICEM CFD

4. For turbomachinery use turbogrid. But it is limited to predefined geometries.

5. Tgrid for very large unstructured meshes and very complex geometries.

For exact advise please tell us the following info:

a) Problem type and geometry. Please past some pics

b) which software(s) is (are) available to you.

stuart23 October 27, 2012 09:39

Great explanation, far.

I am going to bookmark this thread so that for every "what mesh program should I use?" thread, I can just post a link to this! :-)

PS. I should also point out Pointwise. Just got ithere, it looks good, but I haven't had much of a play with it yet.

Far October 27, 2012 11:21

Quote:

Originally Posted by stuart23 (Post 388825)
Great explanation, far.

I am going to bookmark this thread so that for every "what mesh program should I use?" thread, I can just post a link to this! :-)

PS. I should also point out Pointwise. Just got ithere, it looks good, but I haven't had much of a play with it yet.


Thanks Staurt.

Pointwise has the similar capabilities but has the advantage of GUI. But I would say gridgen was very fast as compared to pointwise if you know the hot keys. For example pressing the zero "0" in numeric key board will automatically place the connector or domain at the nearest available point which saves you time. It is also interesting that this technology in not available in any other mesher.

Pointwise has also added the new feature that is extruding the boundary layer normal to wall with capability to project on the normal surface. For example if you have blade and hub configuration. Now if you extrude the boundary layer normal to blade then you project this boundary layer on hub region which not planner surface.

One important point about ICEM Hexa: It has inherent scalability capability. For example if you need half hour for the simple geometry to generate the mesh, you also need almost same order of time to produce the mesh for very complex geometry. This is made possible because you don't really make the each and every vertex, edge, domain and volume mesh. Even you don't need a manual procedure to produce the O-grid.
Once you master the ICEM hexa now you have unlimited power.

cfd seeker November 30, 2012 14:30

Quote:

4. For turbomachinery use turbogrid. But it is limited to predefined geometries.
Can you tell me on which geometries/shapes the use of turbogrid is limited?

Far December 1, 2012 06:52

For example non axi-symmetric hub end wall.

Al-Hashimi December 1, 2012 07:48

I think Gambit is the Easy way to generate your mesh


All times are GMT -4. The time now is 04:48.