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October 27, 2010, 21:30 |
convergence in tetramesh
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#1 |
New Member
KaySee
Join Date: Apr 2010
Posts: 5
Rep Power: 16 |
Hi colleagues:
I would like to gather comments from you all regarding the convergence performance using tetrahedral mesh. I build up my 3D tetrahedral mesh using Delaunay method and find that the convergence is kinda irregular. For a simple incompressible flow condition in a flow distributor at a certain tetrahedral mesh setup, I could not achieve convergence at all. The pressure correction residual error is getting unstable ( residual error goes down to a certain level and it spikes up again). Subsequently, I extract the cells (problematic cell) that contain the largest residual error and try to remesh the region of those problematic cells. In this case, the convergence can be attained. Dear colleagues, I would like to know whether you have come across this phenomenon before? Something come across my mind: for the matrix solver of pressure correction equation, I utilise the Bicgstab method with preconditioner. Could this problem due to the characteristic of the Bicgstab method itself, whereby the error cannot be pushed out from the domain as efficiently as the AMG method, particularly in the unstructured tetrahedral environment? I have not tried the AMG yet. Or, could it be due to any other reasons, which is unknown to me? Thanks. |
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