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-   -   [ICEM] Grid independency study. (https://www.cfd-online.com/Forums/ansys-meshing/182717-grid-independency-study.html)

lovegne January 17, 2017 11:35

Grid independency study.
 
Hello
I have to study grid independency for my problem in Fluent. I have done meshing in ICEM CFD.
Now how should I change the number of cells in ICEM CFD to get the grid independency effects.
Thanks

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Wingman January 17, 2017 16:12

Quote:

Originally Posted by lovegne (Post 633619)
Hello
I have to study grid independency for my problem in Fluent. I have done meshing in ICEM CFD.
Now how should I change the number of cells in ICEM CFD to get the grid independency effects.
Thanks

Sent from my C2004 using CFD Online Forum mobile app

The easiest way would be.
Blocking -> Pre-Mesh Params -> Refinement
Choose all blocks and increase the refinement level.

Then recompute the pre-mesh. I believe that number of nodes will double on for each level.

lovegne January 18, 2017 10:24

With refinement of all blocks, number of nodes get increase to approx 4 times. what I want to increase by 1.5 times. Shall I choose important blocks only?

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Wingman January 18, 2017 14:19

Quote:

Originally Posted by lovegne (Post 633757)
With refinement of all blocks, number of nodes get increase to approx 4 times. what I want to increase by 1.5 times. Shall I choose important blocks only?

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If you have a single rectangle block with edges A, B, C and D. Where A & C and B & D are parallel. In that block the number of nodes is (Na*Nb) = (Nc*Nd)...
Na is number of nodes on edge A e.t.c.

So if
Na = Nc = 100
Nb = Nd = 100

The total number of nodes within the block is 100*100 = 10.000. If we double the nodes per edge we have nodes of 200*200 = 40.000 in the block.

So it depends on your blocking how much the number of nodes increase.

If you want to increase the number of nodes by only 1.5 you would have to change it manually. I would recommend using a replay file try multiplying the node number by ~1.225 to begin with...

lovegne January 19, 2017 02:07

Thanks, I got it

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