Reason of divergence ?

November 29, 2000, 00:51

Hi,

I am writing a finite volume code. But I met a problem. When using finer grids, the computation becomes divergent! What is the reason ?

Thank in advance.

November 29, 2000, 02:05

Please refer to the thread 'convergence problem' in this forum posted by 19/20 Nov. Also look for the archive. If there is any specific topic please leave message for discussion.

November 29, 2000, 14:34

hi there,

What kind of grid arrangement are you using? Staggered or Collocated? If you are using a collocated arrangement, well be sure that you're treating correctly the pressure-velocity coupling.You also need to pay special attention to the velocity correction. Check the following article: Morinishi, Lund, Vasilyev and Moin. "Fully Conservative Higher Order Finite Difference Schemes for Incompressible Flow". J. Comp. Phys 143, 90-124, 1998. Can be downloaded at: http://mae.uta.edu/~lund/ Finally be sure that your time step does verify the CFL condition.

I hope this helps,

Sincerely,

Frederic Felten CFD Laboratory, UT Arlington. http://utacfdb.uta.edu/

December 2, 2000, 23:34

Thank you all!

November 29, 2000, 00:51	Reason of divergence ?	#1
Brayton Guest Posts: n/a	Hi, I am writing a finite volume code. But I met a problem. When using finer grids, the computation becomes divergent! What is the reason ? Thank in advance.

November 29, 2000, 02:05	Re: Reason of divergence ?	#2
Mukhopadhyay Guest Posts: n/a	Please refer to the thread 'convergence problem' in this forum posted by 19/20 Nov. Also look for the archive. If there is any specific topic please leave message for discussion.

November 29, 2000, 14:34	Re: Reason of divergence ?	#3
frederic felten Guest Posts: n/a	hi there, What kind of grid arrangement are you using? Staggered or Collocated? If you are using a collocated arrangement, well be sure that you're treating correctly the pressure-velocity coupling.You also need to pay special attention to the velocity correction. Check the following article: Morinishi, Lund, Vasilyev and Moin. "Fully Conservative Higher Order Finite Difference Schemes for Incompressible Flow". J. Comp. Phys 143, 90-124, 1998. Can be downloaded at: http://mae.uta.edu/~lund/ Finally be sure that your time step does verify the CFL condition. I hope this helps, Sincerely, Frederic Felten CFD Laboratory, UT Arlington. http://utacfdb.uta.edu/

December 2, 2000, 23:34	Re: Reason of divergence ?	#4
Brayton Guest Posts: n/a	Thank you all!

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