I'm wondering why fluxes are m
I'm wondering why fluxes are made relative to the mesh-motion at the end of the PISO loop in icoDyMFoam:
for (int corr=0; corr<nCorr; corr++) { rUA = 1.0/UEqn.A(); } I'm guessing that this is required for the correctBoundaryConditions call for velocity. Can anyone confirm/explain why this is so? |
Hy Sandeep,
If I remember r
Hy Sandeep,
If I remember right is this because of the space conservation law and the additional flux which is associated with a moving boundary (mesh). Jens |
Hi Sandeep,
Read any paper
Hi Sandeep,
Read any paper on Arbitrary Lagrangian Eulerian (ALE) methods and it will all be clear. For example Charbel Farhat, "The Discrete Geometric Conservation Law and the Nonlinear Stability of ALE Schemes for the Solution of Flow Problems on Moving Grids", Journal of Computational Physics 174, 669–694 (2001) or more recent papers on mesh motion by ˇZeljko Tukovi'c. /Eric |
Hello Jens and Eric,
Thanks
Hello Jens and Eric,
Thanks for the help, but it still isn't clear. The makeRelative function merely subtracts meshPhi from phi. However, for the next iteration of the nCorr loop, phi is over-written by: phi = (fvc::interpolate(U) & mesh.Sf()); The line: U -= rUA*fvc::grad(p); doesn't require phi in any way, and the only reason phi should be relative to mesh-motion (in my opinion) is to satisfy a particular boundary-condition (at U.correctBoundaryConditions()) which requires it to be so. If none of the boundary conditions require it, is the line really necessary? Comments? |
Hi Sandeep,
Yes you are rig
Hi Sandeep,
Yes you are right. You will need relative flux at that stage only if velocity boundary condition requires it. But you will also need relative flux in the turbDyMFoam solver because the transport equations of a turbulence model will require relative flux. Regards, Zeljko |
Hello!
This thread has been quiet for a while. But what I don't understand about makeRelative and makeAbsolute is, how makeRelative can be called twice without makeAbsolute in between? The interDyMFoam solver calls: Code:
Abs Here are the relevant calls with all for{} loops and if{} conditions: Code:
while (runTime.run()) Mark |
Hello Mark,
did you find an answer to your question? I'm interested. thanks |
Hello Mark,
Did you find answer to your question? Please let me know . |
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