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-   -   Navier-stokes equations and iterative solver?? (http://www.cfd-online.com/Forums/main/5622-navier-stokes-equations-iterative-solver.html)

wuliang January 10, 2003 07:52

Navier-stokes equations and iterative solver??
 
Hi, everyone,

Now I'm coding the Navier-stokes solver (both for laminar and turbulent cases). Firstly, to make sure the correctness of my laminar code, I use two bechmark testings to check it, one is 2d cavity problem and another is backward facing step problem. To my surprise, these two tests can be correctly solved (seems) by direct solver, but failed by iterative solvers (Im using the ILU/ILUT solver from http://www.osl.iu.edu/research/itl/), so I have several questions:

1)Do you think the results I got are correct or not? The results can be found here:

http://www.mema.ucl.ac.be/~wu/bechma...ity-vector.png

http://www.mema.ucl.ac.be/~wu/bechma...y-pressure.png

http://www.mema.ucl.ac.be/~wu/bechma...ity-vector.png

http://www.mema.ucl.ac.be/~wu/bechma...p-pressure.png

2) Are there anyone here once solved Navier-stokes equations by ILU/ILUT iterative solver successfully? Or using the ITL library to solve N-S equations successfully?

Thanks for your attention.

gita January 10, 2003 12:28

Re: Navier-stokes equations and iterative solver??
 
Hi Wuliang,

Have you run for different Re's? Just take 2D cavity and look at the results. For Re=100 itself,you will observe corner vortices(at the bottom)in the vorticity plot. Comapre it with standard Ghia's results. Run your code(ILU/ILUT)for Re=100 for driven cavity case and see whther your code produces those corner eddies. Gita

Ist January 13, 2003 23:28

Re: Navier-stokes equations and iterative solver??
 
I think you have to run for different Re in the range of laminar up to turbulent. So, for the various Re, you can also look for their influence to fluid flow profile, especially at the solid blocking. Good luck for you...


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