On Thu, Apr 21, 2011 at 7:07 AM, TAY wee-beng <span dir="ltr"><<a href="mailto:zonexo@gmail.com">zonexo@gmail.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hi,<br>
<br>
Since there is a similar topic on improving performance of CFD using PETSc earlier, I hope to improve my current CFD solver performance too.<br>
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I wrote it in Fortran90 with MPI. It is a Immersed Boundary Method (IBM) Navier-Stokes Cartesian grid solver in 2D, although I hope to extend it to 3D in the future. I solve the NS equations using fractional step which results in 2 equations - the momentum and Poisson equations. They are then linearized into systems of equations.<br>
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I currently solve the momentum solver using PETSc with KSPBCGS. For the Poisson equation, I was using hypre's BoomerAMG. But I have changed to using the geometric multigrid solver from hypre since it's slightly faster.<br>
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Currently, I am dividing my grid along the y direction for MPI into equal size for each processor. I guess this is not very efficient since beyond 4 processors, the scaling factor drops.<br>
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I think implementing the distributed array should increase performance, is that so? I wonder how difficult it is because most examples are in C and I am not so used to that. I am also using staggered grid but I will most likely changed to a collocated grid arrangement.<br>
</blockquote><div><br></div><div>It will definitely improve scalability. I don't think conversion should be that hard.</div><div><br></div><div> Matt</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
What other suggestions do you have to improve the solver's performance using PETSc?<br>
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Thank you very much.<br>
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Yours sincerely,<br><font color="#888888">
<br>
TAY wee-beng<br>
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</font></blockquote></div><br><br clear="all"><br>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener<br>