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name August 24, 2001 04:15

[difference ; SIP, CGS ?]
hi all. Strongly Implicit Procedure, Conjugate Gradient. Which one is better ? (I need faster solver...) thx.

PCCG-SIP August 25, 2001 11:54

Re: [difference ; SIP, CGS ?]
Depends on the problem at hand. I would suggest learning about each solver (there is a e-book online here somewhere Templates of Liner solvers or somthing like that).

I see alot of Stone solvers in SIMPLE Codes... More and More I am seeing the use of Conjugate Gradient as a preconditioner then the stone algorithm is applied...

there is a good tutorial of congugate gradients on-line somewhere... (An introduction to the conjugate gradient method without the agonizing pain by Jonathan Shewchuk)

Abhijit Tilak August 25, 2001 21:06

Re: [difference ; SIP, CGS ?]

Neither of what u said is as good as MSIP, Modified Stone's Solver by Schnider & Zedan. Phoenics uses MSIP for Pres. Correction equation. CGS/PCGS can be used for P' equation bcos the coeff matrix is symmetric. for Momentum/energy equn's the upwinding & other host of schemes will destroy symmetry of coeff matrix. CGS is not applicable directly then. Hope this helps Abhijit

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