CFD Online Logo CFD Online URL
Home > Forums > General Forums > Main CFD Forum

Mesh Independence - Valid Strategy?

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   August 27, 2009, 08:04
Default Mesh Independence - Valid Strategy?
New Member
Join Date: Mar 2009
Posts: 9
Rep Power: 17
Ianto is on a distinguished road
Dear All,

I'm running a mesh independance study - solve same problem on coarse, medium & fine meshes & examining solution from each, in the hope my parameter (head loss) converges towards the analytical solution as the mesh is refined & gives an indication of the mesh size necessary for acceptably small error. I have a convoluted passage which is my geometry of interest, to which I've added artificial inlet and outlet extensions. At the end of these I apply boundary conditions.

My question is with an eye on maintaining manageable mesh sizes - am I correct in thinking I can leave areas of the mesh which aren't of interest (extended inlet and outlets) unrefined, and only refine the areas I am studying? Is this still a valid mesh dependance study?


Ianto is offline   Reply With Quote

Old   August 27, 2009, 08:17
Join Date: Mar 2009
Posts: 55
Rep Power: 17
SKK is on a distinguished road
In any kind of meshing, it is necessarry to have smooth transition between mesh sizes. So, if you are refining your mesh in the region of importance, you would have to refine your mesh in the extruded regions (especially near the interface of your interior to boundary region) aswell so the gradients etc are calculated properly and so their effect on the interior mesh. The mesh in outlet region will perhaps have more effect in the solution than that at the inlet owing to the effect of boundary values on the calculation of the interior cells.
SKK is offline   Reply With Quote

Old   August 31, 2009, 04:36
New Member
Join Date: Apr 2009
Posts: 29
Rep Power: 17
shyamdsundar is on a distinguished road
If I am right, what you intended to do is local refinement. It could give you a (grid) converged solution. But, what you are trying to do is to remove the errors only in that region. You still need to be sure that the errors generated in the rest of the region is smaller than the region of interest (which you refined). To check it, you can probably do two grid refinements (coarse to medium) with first one refined locally, and second one refined globally.
shyamdsundar is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
[Other] vtk mesh or Abaqus mesh to OpenFOAM bigphil OpenFOAM Meshing & Mesh Conversion 27 November 23, 2015 17:31
fluent add additional zones for the mesh file SSL FLUENT 2 January 26, 2008 11:55
basic of mesh refinement arya CFX 4 June 19, 2007 12:21
unstructured mesh grid independence for Fluent Shane Schouten FLUENT 0 October 11, 2006 16:50
Mesh Independence and Y + sam FLUENT 1 September 13, 2006 05:50

All times are GMT -4. The time now is 04:52.