# FOAM WARNING at time

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 March 21, 2013, 04:51 FOAM WARNING at time #1 Member   v Join Date: Nov 2011 Posts: 33 Rep Power: 6 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

 March 22, 2013, 01:48 #2 Senior Member   Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,195 Blog Entries: 1 Rep Power: 16 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 __________________ Telegram channel (https://telegram.me/openfoam4Iranian) My Weblog (http://openfoam.blogfa.com/) Training Course on OpenFOAM at (http://www.isme.ir/)

 March 22, 2013, 02:38 #3 Senior Member   Lieven Join Date: Dec 2011 Location: Leuven, Belgium Posts: 297 Rep Power: 14 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

 March 22, 2013, 03:45 #4 Member   v Join Date: Nov 2011 Posts: 33 Rep Power: 6 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

 March 22, 2013, 16:00 #5 Senior Member   Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,195 Blog Entries: 1 Rep Power: 16 i suggest to add source in several points instead of one point!, it may solves problem __________________ Telegram channel (https://telegram.me/openfoam4Iranian) My Weblog (http://openfoam.blogfa.com/) Training Course on OpenFOAM at (http://www.isme.ir/)

 March 23, 2013, 07:35 #6 Member   v Join Date: Nov 2011 Posts: 33 Rep Power: 6 thanks your reply i did this work but it did not difference!!

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