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Old   April 21, 2004, 12:47
Default transient pressure correction
  #1
dominique
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hi,

i'm doing pseudo-compressibility pressure correction in transient low R_e flow in a tube (2D). how do I choose optimal ratio between dt for velocity update and (pseudo) dt for pressure correction? in particular: is it better to do more velocity corrections and few pressure corrections or vice versa?

thank you.
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Old   April 22, 2004, 07:51
Default Re: transient pressure correction
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vesi
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If you are using pseudo-compressibility method, then pressure is also updated via time or pseudo time marching, then you do the same times of corrections to both V and P.
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Old   April 22, 2004, 17:03
Default Re: transient pressure correction
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dominique
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you mean, correct velocity, correct pressure and again, in a loop? yes, that is clear, but what about "dt", how do I set optimal relation between two delta t's for both explicit time marching...?

thanks domi
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Old   April 23, 2004, 05:29
Default Re: transient pressure correction
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versi
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Years Ago AIAA Journal had papers discussing pseudo time sep and physical time step. The pseuodtime step has the meaning of relaxation factor, it can be larger than a nondimensional physical Dt. may be 10 times up, I remebered. If the inner iteration is implicit can be 10^12 up. (== discarding it at all)
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Old   April 23, 2004, 11:14
Default Re: transient pressure correction
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centaur_ks
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read paper on dual time step approch , try one by Yoon and Jameson on LU-SSOR for eular and NS eqn and there are some more by Jameson that explains dual time stepping approch quite well.
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Old   May 27, 2004, 08:03
Default Harlow & Amsden
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enis
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Hello everyone,

Is there anybody who are using IMF(Implicit Multifield Model of Harlow & Amsden) technique for their studies?I want to ask some questions.

thanks
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