# problem regarding solver running two times

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 October 19, 2023, 04:08 problem regarding solver running two times #1 New Member   Vishal Garg Join Date: Jun 2023 Posts: 13 Rep Power: 2 Hello everyone, I am running chtmultiregionsimplefoam for solving solid and fluid regions in concentric cylinder. Now the problem i am facing is that the solver is running two times for pipe_1 and pipe_2 and p_rgh for water region. can anyone tell me why solver is solving these for two times? I am attaching the simulation. Thanks in advance Time = 8488 Solving for fluid region water DILUPBiCGStab: Solving for Ux, Initial residual = 2.507399e-08, Final residual = 1.415443e-10, No Iterations 1 DILUPBiCGStab: Solving for Uy, Initial residual = 5.153429e-08, Final residual = 2.864192e-10, No Iterations 1 DILUPBiCGStab: Solving for Uz, Initial residual = 3.702059e-09, Final residual = 3.702059e-09, No Iterations 0 DILUPBiCGStab: Solving for h, Initial residual = 6.314294e-05, Final residual = 5.728423e-07, No Iterations 1 limitTemperature limitT Lower limited 0 (0%) of cells, with min limit 300 limitTemperature limitT Upper limited 0 (0%) of cells, with max limit 465 limitTemperature limitT Unlimited Tmin 300.0003 limitTemperature limitT Unlimited Tmax 391.0836 Min/max T:300 400 GAMG: Solving for p_rgh, Initial residual = 1.410428e-07, Final residual = 9.999433e-08, No Iterations 24 GAMG: Solving for p_rgh, Initial residual = 9.999433e-08, Final residual = 9.999433e-08, No Iterations 0 time step continuity errors : sum local = 5.658036e-07, global = -8.6012e-09, cumulative = -0.04589086 Min/max rho:1000 1000 DILUPBiCGStab: Solving for epsilon, Initial residual = 9.982368e-09, Final residual = 9.982368e-09, No Iterations 0 DILUPBiCGStab: Solving for k, Initial residual = 1.405872e-08, Final residual = 8.006672e-11, No Iterations 1 Solving for solid region pipe_1 GAMG: Solving for h, Initial residual = 2.577401e-05, Final residual = 1.875361e-10, No Iterations 1 limitTemperature limitT Lower limited 0 (0%) of cells, with min limit 300 limitTemperature limitT Upper limited 0 (0%) of cells, with max limit 465 limitTemperature limitT Unlimited Tmin 300.8637 limitTemperature limitT Unlimited Tmax 387.3766 Min/max T:300.7518 387.8024 Solving for solid region pipe_1 GAMG: Solving for h, Initial residual = 2.487348e-05, Final residual = 1.29597e-10, No Iterations 1 limitTemperature limitT Lower limited 0 (0%) of cells, with min limit 300 limitTemperature limitT Upper limited 0 (0%) of cells, with max limit 465 limitTemperature limitT Unlimited Tmin 300.8638 limitTemperature limitT Unlimited Tmax 387.3776 Min/max T:300.7519 387.8031 Solving for solid region pipe_2 GAMG: Solving for h, Initial residual = 1.123358e-06, Final residual = 2.516377e-11, No Iterations 1 limitTemperature limitT Lower limited 0 (0%) of cells, with min limit 300 limitTemperature limitT Upper limited 0 (0%) of cells, with max limit 465 limitTemperature limitT Unlimited Tmin 300.0083 limitTemperature limitT Unlimited Tmax 399.3518 Min/max T:300.0078 400 Solving for solid region pipe_2 GAMG: Solving for h, Initial residual = 1.088135e-06, Final residual = 2.445573e-11, No Iterations 1 limitTemperature limitT Lower limited 0 (0%) of cells, with min limit 300 limitTemperature limitT Upper limited 0 (0%) of cells, with max limit 465 limitTemperature limitT Unlimited Tmin 300.0083 limitTemperature limitT Unlimited Tmax 399.3518 Min/max T:300.0078 400 ExecutionTime = 145336.9 s ClockTime = 145347 s

 October 19, 2023, 04:22 #2 Senior Member   Join Date: Dec 2021 Posts: 186 Rep Power: 4 Hey! I believe it is a normal behavior when you set nNonOrthogonalCorrectors to 1 or more in the fvSolution files of the different regions. If you want just one iteration, set it to zero. But if your mesh has some non-orthogonality, it may help with convergence to leave it at 1 or more, especially for fluid regions.