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pisoFoam gets stuck with no error and little cournant number |
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April 4, 2020, 03:38
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pisoFoam gets stuck with no error and little cournant number
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#1 |
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New Member
Xiangjie Wang
Join Date: Jul 2019
Posts: 26
Rep Power: 7  |
Dear Foamers,
I am running a pisoFoam in a cluster. At the first stage, I tried running it in one node with 16 processors. It goes well but a little slowly. The time step is 0.001s and finally, I got a 3.6s data in 12 hours. Then I terminated it. There are 5.6M cells. Then I tried to run it in 16 nodes with 256 processors in total to speed up. It was indeed faster than before, but it was stuck at 0.162s for once and 0.17s for another time. The same situation happened when I used 8 nodes with 128 processors. The courant number is 0.225 with the maximum is 0.315 before it got stuck. I am using a pisoFoam solver and a synthetic method to generate the inflow boundary condition. I think it might also get stuck when I run it in one node. Code:
Time = 0.168 Courant Number mean: 0.2252957 max: 0.3151702 Patch: inlet recycled 3 eddies mass flow correction coefficient: 1.005238 smoothSolver: Solving for Ux, Initial residual = 0.005431484, Final residual = 3.443522e-07, No Iterations 4 smoothSolver: Solving for Uz, Initial residual = 0.00986471, Final residual = 6.099746e-07, No Iterations 4 GAMG: Solving for p, Initial residual = 0.1917015, Final residual = 0.01027828, No Iterations 2 time step continuity errors : sum local = 8.542895e-07, global = 6.909716e-10, cumulative = -8.085466e-07 GAMG: Solving for p, Initial residual = 0.01235708, Final residual = 8.729178e-07, No Iterations 21 time step continuity errors : sum local = 7.655085e-11, global = -5.037762e-13, cumulative = -8.085471e-07 ExecutionTime = 440.13 s ClockTime = 426 s Time = 0.169 Courant Number mean: 0.2252872 max: 0.3151045 Patch: inlet recycled 4 eddies mass flow correction coefficient: 1.005221 smoothSolver: Solving for Ux, Initial residual = 0.004916222, Final residual = 3.063116e-07, No Iterations 4 smoothSolver: Solving for Uz, Initial residual = 0.009755776, Final residual = 6.022459e-07, No Iterations 4 GAMG: Solving for p, Initial residual = 0.1274995, Final residual = 0.008578488, No Iterations 2 time step continuity errors : sum local = 7.616146e-07, global = -1.088968e-10, cumulative = -8.08656e-07 GAMG: Solving for p, Initial residual = 0.009608369, Final residual = 8.486479e-07, No Iterations 21 time step continuity errors : sum local = 7.726608e-11, global = 7.693458e-13, cumulative = -8.086552e-07 ExecutionTime = 442.66 s ClockTime = 429 s Time = 0.17 Courant Number mean: 0.2252813 max: 0.3153122 Patch: inlet recycled 7 eddies mass flow correction coefficient: 1.00542 Does anyone have any suggestions? I would really appreciate it if you can give me some suggestions! Bests, Xiangjie |
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April 4, 2020, 04:04
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#2 | |
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New Member
Xiangjie Wang
Join Date: Jul 2019
Posts: 26
Rep Power: 7 |
I forgot to mention that I tried to delete the latest time step file and run pisoFoam again starting from the latest time step, like in this case I deleted the file 0.17 and ran pisoFoam from 0.169, then it can run for a while but will still get stuck at some time step later.
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