coalChemistryFoam stuck at "solving 3D cloud coalCould1"
Hi, CFDers,
I am a beginner. I want to use the lagrangian/coalChemistrySolver to simulate a fludized bed. Everything goes smoothly in the beginning. I manually gave the position of particles, changed mesh( I used the MPPIC/Goldschmidt mesh), and changed the BCs. Then, it runned well in the first 3 or 4 steps, but stuck at the "solving the 3D limestone1Cloud". So I guess there must be problems in limestone, and I removed the limestone cloud. I deleted the codes concerning the limestone in the coalChemistryFoam solver, and constructed my own solver. Next, I changed the cases, delete everything about limestone as well. However, it stuck again, but at this time, it runned the first 40 steps successfully. It stuck at "solving 3D cloud coalCloud1" for over a whole day. (PS: I didn't use the parallel running) Here is the message of the last full step. (VERSION: OpenFOAM 5.0) ********************This is the reporting messege************************* Solving 3D cloud coalCloud1 Cloud: coalCloud1 Current number of parcels = 15 Current mass in system = 9.732826e05 Linear momentum = (4.640577763e22 5.169686395e06 7.957195454e11) Linear momentum = 5.169686395e06 Linear kinetic energy = 2.182705169e06 model1: number of parcels added = 15 mass introduced = 0.0001 Parcel fate (number, mass)  escape = 0, 0  stick = 0, 0 Temperature min/max = 395.934319, 3714.657715 Mass transfer phase change = 2.6e06 Mass transfer devolatilisation = 7.174e08 Mass transfer surface reaction = 0 diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0 PIMPLE: iteration 1 smoothSolver: Solving for Ux, Initial residual = 0.02700502602, Final residual = 4.27820528e07, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 0.1531300513, Final residual = 5.563320449e06, No Iterations 2 smoothSolver: Solving for Uz, Initial residual = 0.3387311746, Final residual = 5.81888811e06, No Iterations 2 smoothSolver: Solving for O2, Initial residual = 0.03372301324, Final residual = 0.0001458607168, No Iterations 1 smoothSolver: Solving for CH4, Initial residual = 1, Final residual = 0.0058086625, No Iterations 1 smoothSolver: Solving for H2, Initial residual = 1, Final residual = 0.0058086625, No Iterations 1 smoothSolver: Solving for CO2, Initial residual = 1, Final residual = 0.0058086625, No Iterations 1 smoothSolver: Solving for H2O, Initial residual = 0.01647708143, Final residual = 4.63638096e05, No Iterations 1 smoothSolver: Solving for h, Initial residual = 0, Final residual = 0, No Iterations 0 DICPCG: Solving for G, Initial residual = 0.08545688571, Final residual = 8.279370758e06, No Iterations 29 T gas min/max = 400, 2000 GAMG: Solving for p, Initial residual = 0.9804021843, Final residual = 0.009763620485, No Iterations 27 diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0 time step continuity errors : sum local = 0.0003890516732, global = 4.274753778e06, cumulative = 2.041892519e05 GAMG: Solving for p, Initial residual = 0.2044590547, Final residual = 0.001898141125, No Iterations 24 diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0 time step continuity errors : sum local = 7.382094053e05, global = 6.815163749e07, cumulative = 2.110044156e05 GAMG: Solving for p, Initial residual = 0.01425715074, Final residual = 9.899799564e07, No Iterations 64 diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0 time step continuity errors : sum local = 3.253106828e08, global = 4.282165798e10, cumulative = 2.110001335e05 ExecutionTime = 10.32 s ClockTime = 11 s Courant Number mean: 0.1268739922 max: 0.2799631762 deltaT = 0.0005 Time = 0.101 Solving 3D cloud coalCloud1 ********************This is the end of reporting message************************* Boundary Condition is as follows ********************This is the Boundary Condition************************************** ************************************************** ************************************** ********************Boundary Condition of "alphat"************************* internalField uniform 0; boundaryField { top { type compressible::alphatWallFunction; value uniform 0; } bottom { type compressible::alphatWallFunction; value uniform 0; } walls { type compressible::alphatWallFunction; value uniform 0; } frontAndBack { type wall; } } ********************end of "alphat"************************* ********************Boundary Condition of "CH4"************************* internalField uniform 0; boundaryField { top { type zeroGradient; } bottom { type zeroGradient; } walls { type zeroGradient; } frontAndBack { type zeroGradient; } } ********************end of "CH4"************************* Other gases, i.e. "O2, CO2, CO, N2, H2, H2O" is exactlly the same with "CH4" ********************Boundary Condition of "G"************************* internalField uniform 0; boundaryField { top { type MarshakRadiation; emissivityMode lookup; emissivity uniform 1; value uniform 0; } bottom { type MarshakRadiation; emissivityMode lookup; emissivity uniform 1; value uniform 0; } walls { type MarshakRadiation; emissivityMode lookup; emissivity uniform 1; value uniform 0; } frontAndBack { type MarshakRadiation; emissivityMode lookup; emissivity uniform 1; value uniform 0; } } ********************end of "G"************************* ********************Boundary Condition of "p"************************* internalField uniform 100000; boundaryField { top { type zeroGradient; } bottom { type zeroGradient; } walls { type zeroGradient; } frontAndBack { type zeroGradient; } } ********************end of "p"************************* ********************Boundary Condition of "U"************************* internalField uniform ( 0 0 0 ); boundaryField { top { type noSlip; } bottom { type noSlip; } walls { type noSlip; } frontAndBack { type noSlip; } } ********************end of "U"************************* ********************Boundary Condition of "T"************************* internalField uniform 400; boundaryField { top { type zeroGradient; } bottom { type zeroGradient; } walls { type fixedValue; value uniform 400; } frontAndBack { type zeroGradient; } } ********************end of "T"************************* ********************end of all Boundary Conditions************************************** ************************************************** ************************************** The injection of particles is manually injected in the beginning, as the original coalChemistryFoam/simplifiedSiwek example case does. The position are: (totally 15 coalParticles) ( (0.0 0.03 0.15) (0.0 0.00 0.15) (0.0 0.03 0.15) (0.0 0.03 0.18) (0.0 0.00 0.18) (0.0 0.03 0.18) (0.0 0.03 0.21) (0.0 0.00 0.21) (0.0 0.03 0.21) (0.0 0.03 0.24) (0.0 0.00 0.24) (0.0 0.03 0.24) (0.0 0.03 0.27) (0.0 0.00 0.27) (0.0 0.03 0.27) ) Mesh is using the example case of MPPICFoam/Goldschmidt, i.e., a 15*45 grids plane, the thick is one grid. The controlDict is as follows: // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // application coalChemistryFoam; startFrom startTime; startTime 0; stopAt endTime; endTime 0.5; deltaT 0.0001; writeControl adjustableRunTime; writeInterval 0.0025; purgeWrite 0; writeFormat ascii; writePrecision 10; writeCompression off; timeFormat general; timePrecision 6; runTimeModifiable true; adjustTimeStep yes; maxCo 1.0; maxDeltaT 1; // ************************************************** *********************** // 
I changed the BC as follows:
p: bottom uniform 1e5 N2: bottom uniform 0.79 O2: bottom uniform 0.21 At present, it goes beyond where I stuck before. 
Did you find a solution for your problem? I also encountered the same problem in my simulation.

Can anyone give some comments on this point?
Any comment is appreciated. 
All times are GMT 4. The time now is 18:41. 