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Old   September 11, 2001, 03:33
Default convergence
  #1
sreekanth
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What is the efect of cell size on convergence rate, using unstructured grid.
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Old   September 11, 2001, 05:14
Default Re: convergence
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Jin-Wook LEE
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Ingeneral, cell size itself has not the major effect on the convergence. But, in general, coarse grid has better convergence. Mesh skewness, edge ratio(dx_i/dx_(i-1) ...) and aspect ratio have critical effect on the convergence.

Sincerely, Jinwook
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Old   September 11, 2001, 22:13
Default Re: convergence
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Dan Williams
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What type of convergence do you mean in this case? Convergence to a mesh independent solution, which is somewhat tricky to guage on an unstructured grid. Or, convergence of residuals of algebraic equations?

Dan.
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Old   September 12, 2001, 03:38
Default Re: convergence
  #4
sreekanth
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The convergence in FEM used to unstructured grids is of the order of cube of h(cell size parameter,less than 1.0).

What is the trend in FVM used to unstructured grid?
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Old   September 12, 2001, 05:12
Default Re: convergence
  #5
Kang, Seok Koo
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The convergence always depends on the CFL number when we use explicit scheme. CFL number on unstructured grid generally depend on the volume/area of a control volume.

When the mesh size is very small, the time step must be reduced to get the converged solution.

In my experience, if a mesh is not highly stretched, geometry of a mesh is not an important factor.
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