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arya June 19, 2007 05:28

basic of mesh refinement

I am consider my self as novice in this area and I would like to ask about mesh refinement. First I would like to explain steps which I have done so far :

- I create my 3d model using proe and export it to icem in iges format.

-I did some cleaning and assigned my parts.

-I create my mesh as unstructured tetrahedral and this are the things I did while preparing my mesh :

a. In Global Mesh Setup, I did not change anything. b. In mesh sizes for parts, I only assigned the individual max size for each part that I have. My understanding is the smaller the maximum size, the finer the mesh (I am not sure about this). The biggest is 8 and smallest is 0.5 c. I do nothing for surface mesh setup as well for curve mesh setup d. Last thing is I compute my mesh

- After finish with computing the mesh, I choose edit mesh and activate smooth mesh globally. There I choose my smoothing iterations to be 6 and up to value 0.8 (the bigger the better isn't it?)

- After applying the smooths elements globally I choose check mesh, I got no error message except for unconnected vertices.

- And that will be the end of my step

The problem happens when I run in fluent, my residual seems to be fluctuating and my supervisor advise me to refine my mesh, but I have no idea what to do? and how to check my mesh.

Any suggestions?


Albi June 19, 2007 06:00

Re: basic of mesh refinement
I am not sure that your problems are due to mesh. If you have any problems with convergence, you can try to refine that, but probably a change of the timescale will be more appropriate.

How much you can rifine your mesh depends on your computational resources and the time you are disposed to spend to obtain a solution.



arya June 19, 2007 07:18

Re: basic of mesh refinement
Thanks for the response. What do you mean by time scale? How can I change that value?

Albi June 19, 2007 08:14

Re: basic of mesh refinement
I don't know FLUENT in details. In CFX (this is CFX forum) the timescale is the integration time for the Navier-Stokes equations and you can change it on the solver control panel. I don't know if there is an equivalent parameter in FLUENT, but i suppose there is. Try asking to fluent users in the fluent user forum.

arya June 19, 2007 12:21

Re: basic of mesh refinement
Thanks, I 'll check in fluent.

Anyway is there any suggestion to refine my mesh? What about my mesh size which I've given? Is it sufficient, or is there any step that I missed during mesh generation?

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