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March 21, 2013, 03:51 |
FOAM WARNING at time
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#1 |
Member
v
Join Date: Nov 2011
Posts: 33
Rep Power: 14 |
hi foamers,
This warning is encountered during implementation. And the solution is diverging. //-------------- Courant Number mean: 4.89667e-05 max: 0.488398 deltaT = 1.06092e-56 --> FOAM Warning : From function Time:perator++() in file db/Time/Time.C at line 1010 Increased the timePrecision from 519 to 520 to distinguish between timeNames at time 0.209868 Time = 0.209868454511289076469537917546404059976339340209 9609375 //-------------------------------- How can I solved this warning. best regards |
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March 22, 2013, 00:48 |
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#2 |
Senior Member
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,266
Blog Entries: 1
Rep Power: 24 |
hi dear vahid
deltaT = 1.06092e-56 is so little, so you should decrease your time step in controlDict to remove this warning. how much time do you want to simulate? (1 sec, 1 min, ....) however this little time step shows, some where your solver works wrong! i recommend to check up your BC or your implantation because with this small time step , for and ordinary time it would take so so long time
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March 22, 2013, 01:38 |
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#3 |
Senior Member
Lieven
Join Date: Dec 2011
Location: Leuven, Belgium
Posts: 299
Rep Power: 22 |
Indeed, this could be an indication that something is wrong with the BC like nimasam says. But it might also be that you started with a too big Courant number (~too big time step), this can create instabilities with extremely small time steps as a result. And last, it could also be caused by badly chosen initial conditions. Taking a small time step at the beginning of the run could correct for this.
Cheers, L |
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March 22, 2013, 02:45 |
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#4 |
Member
v
Join Date: Nov 2011
Posts: 33
Rep Power: 14 |
hi
I'm modeling combustion with reactingFoam solver . i used to start the combustion from energy source in the energy equation at Specific time. After applying the energy source comes up warning. //-------------- energySource1 { type scalarExplicitSource; active true; timeStart 0.2; duration 0.05; selectionMode points; points ( (0.067 0.00035 -0.01) ); scalarExplicitSourceCoeffs { volumeMode absolute; injectionRate { hs 2; } } } //----------------------------------- best reagard |
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March 22, 2013, 15:00 |
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#5 |
Senior Member
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,266
Blog Entries: 1
Rep Power: 24 |
i suggest to add source in several points instead of one point!, it may solves problem
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March 23, 2013, 06:35 |
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#6 |
Member
v
Join Date: Nov 2011
Posts: 33
Rep Power: 14 |
thanks your reply
i did this work but it did not difference!! |
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