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Poisson equation in custom solver diverges for large boundary values |
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#1 |
Senior Member
Bobby
Join Date: Oct 2012
Location: Michigan
Posts: 454
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Dear Fellows
I have written a non-dimensional custom solver based on interFoam in OpenFoam 2.1.x. In this solver there is a Poisson equation which is solved for a custom variable. (here ![]() However, my solver crashes by insanely reducing time step if I increase the Dirichlet values at the boundaries. The snippet related to Poisson equation is as follows: Code:
fvScalarMatrix UeEqn ( fvm::laplacian(eps,Ue) == -rhoE * gamma ); UeEqn.solve(); These are my relevant settings in fvSolutions and fvSchemes files: Code:
"(Ue|UeExt)" { solver PCG; preconditioner DIC; tolerance 1e-14; relTol 0.0; }; Code:
laplacianSchemes { default Gauss linear corrected; } ![]()
Has any body experienced this issue or any suggesstion?? Thanks |
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#2 |
Super Moderator
Tobias Holzmann
Join Date: Oct 2010
Location: Bad Wörishofen
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Hi Bobi,
I have no idea about your solver and equations and I also never had »large boundary value problems (whatever large means)« ... one thing that might help. Under relaxation and making outer loops till the equation converged. Or field relaxation. For the pressure (poission eqn) we also use field relaxation. Out of the box I have no other idea -- sorry.
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Keep foaming, Tobias Holzmann |
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#3 |
Senior Member
Bobby
Join Date: Oct 2012
Location: Michigan
Posts: 454
Rep Power: 15 ![]() |
Thanks Tobi
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