CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CFX (
-   -   meshing a sharp edge (

line November 2, 2002 05:39

meshing a sharp edge

I am already frustrated by the meshing process. Can anyone suggest a reading/hint/trick for me to handle the job. Should I be an expert of topology to work on this code?

I have 2 problem, please give me some idea. Thanks (1) I have to model a wind tunnel with 60m long and testing cross section is 3mto 2m. Inside the turning angle, there is a 10 guard vane which is 8mm thick. That means the overall dimension range from 8mm to 60m. Will it cause problem to the code if the size different from 3~4 magnitude of order? I already notice that, from Dave, I can use the thin film to handle the 8mm guard vane. But I have 10 guard vane? It seems it work for 3 guard vane but no more than 3!!!

(2) I have an very geometry which is for teaching purpose. It is defined by the point as a near triangle shape(with 2 side is straight line and one side is parabola) normal to x-plane with one edge connected to the sqaure in other plane. I know there is a small angle problem. I have try to put one more point into the parabola side to construct a trimmed surface. But the meshin process still fail!!!!!

Is it common problem to the code?

Thanks line

Astrid November 2, 2002 08:03

Re: meshing a sharp edge
Regarding problem 1:

- 3 to 4 orders of magnitude should not be the problem. I wonder what the effect of 8 mm will be on a wind tunnel of 60 m, and the other way around, but that is a different question.

- It should be possible to define 10 subdomains which gives you the possiblity to define 10 thin surfaces. Forget inflation on the thin surfaces.

- How are your surface meshes?

- Did you get a volume mesh if you write out a definition file without inflation?

Regarding problem 2:

- Does the meshing problem fails when you write out a definition file or does it already fail when you write out a surface mesh.

- Standard question: have you tried the AFI surface mesher instead of the standard Delauney surface mesher?

- How worse is your worst angle?


Hannah liang November 2, 2002 12:19

Re: meshing a sharp edge
My experience is to use the 8mm gap of guide vane instead of the thin wall, then build B-rep solid in this area. In this way you can add inflation when you write the def.

All times are GMT -4. The time now is 04:41.