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Jetfire November 10, 2014 00:52

@RodriguezFatz
Code:

Does the omega-bounding vanish, if you use the laplacian-setting I suggested?
I tried changing the Laplacian Setting to Gauss Linear uncorrected while the simulation was running. Here is the output , Omega is not bounded in later time steps.
Code:

Courant Number mean: 0.000113778 max: 1
deltaT = 1.41782e-09
Time = 6.59824e-07

solidBodyMotionFunctions::rotatingMotion::transformation(): Time =  6.59824e-07 transformation: ((0 0 0) (0.999946 (0.0103643 0 0)))
AMI: Creating addressing and weights between 1900 source faces and 32076 target faces
AMI: Patch source sum(weights) min/max/average = 0.995413, 1, 0.999762
AMI: Patch target sum(weights) min/max/average = 0.474286, 1.00002, 0.996806
AMI: Creating addressing and weights between 17748 source faces and 5456 target faces
AMI: Patch source sum(weights) min/max/average = 0.443604, 1.05059, 1.00015
AMI: Patch target sum(weights) min/max/average = 0.519849, 1.00249, 0.999845
AMI: Creating addressing and weights between 17839 source faces and 1957 target faces
AMI: Patch source sum(weights) min/max/average = 0.86998, 1, 0.999108
AMI: Patch target sum(weights) min/max/average = 0.991279, 1, 0.99992
GAMG:  Solving for pcorr, Initial residual = 1, Final residual = 0.00915686, No Iterations 54
GAMG:  Solving for pcorr, Initial residual = 0.0243898, Final residual = 0.00464874, No Iterations 1
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
rhoEqn max/min : 2.2097 0.276597
smoothSolver:  Solving for Ux, Initial residual = 3.16377e-05, Final residual = 2.14271e-09, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 0.00139322, Final residual = 1.18808e-07, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 0.00157917, Final residual = 1.27902e-07, No Iterations 1
smoothSolver:  Solving for h, Initial residual = 0.000472102, Final residual = 3.83132e-08, No Iterations 1
GAMG:  Solving for p, Initial residual = 6.76418e-05, Final residual = 2.45351e-13, No Iterations 1
GAMG:  Solving for p, Initial residual = 1.21131e-09, Final residual = 1.21131e-09, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000171506, global = -0.000151276, cumulative = -0.0929682
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.15378e-07, Final residual = 1.15378e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.15378e-07, Final residual = 1.15378e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000171515, global = -0.000151276, cumulative = -0.0931195
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.153e-07, Final residual = 1.153e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.153e-07, Final residual = 1.153e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000171515, global = -0.000151276, cumulative = -0.0932708
rho max/min : 2 0.5
smoothSolver:  Solving for omega, Initial residual = 2.11641e-06, Final residual = 1.37612e-10, No Iterations 1
bounding omega, min: -6204.38 max: 6.34422e+09 average: 2.18357e+06
smoothSolver:  Solving for k, Initial residual = 2.41327e-05, Final residual = 9.59219e-10, No Iterations 1
ExecutionTime = 70114.9 s  ClockTime = 94366 s

regIOobject::readIfModified() :
    Re-reading object fvSchemes from file  "/home/eatin/OpenFOAM/eatin-2.3.0/run/tutorials/TurboCharger/Trial_run/system/fvSchemes"
Courant Number mean: 0.00011376 max: 1
deltaT = 1.41782e-09
Time = 6.61242e-07

solidBodyMotionFunctions::rotatingMotion::transformation(): Time =  6.61242e-07 transformation: ((0 0 0) (0.999946 (0.0103866 0 0)))
AMI: Creating addressing and weights between 1900 source faces and 32076 target faces
AMI: Patch source sum(weights) min/max/average = 0.995413, 1, 0.999762
AMI: Patch target sum(weights) min/max/average = 0.474033, 1, 0.996806
AMI: Creating addressing and weights between 17748 source faces and 5456 target faces
AMI: Patch source sum(weights) min/max/average = 0.439444, 1.05157, 1.00015
AMI: Patch target sum(weights) min/max/average = 0.519845, 1.00248, 0.999845
AMI: Creating addressing and weights between 17839 source faces and 1957 target faces
AMI: Patch source sum(weights) min/max/average = 0.86998, 1, 0.999108
AMI: Patch target sum(weights) min/max/average = 0.991279, 1, 0.99992
GAMG:  Solving for pcorr, Initial residual = 1, Final residual = 0.00996615, No Iterations 57
GAMG:  Solving for pcorr, Initial residual = 1.31767e-05, Final residual = 1.31767e-05, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
rhoEqn max/min : 2.02652 0.480629
smoothSolver:  Solving for Ux, Initial residual = 3.16636e-05, Final residual = 2.11836e-09, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 0.00140312, Final residual = 1.13106e-07, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 0.00159988, Final residual = 1.2634e-07, No Iterations 1
smoothSolver:  Solving for h, Initial residual = 0.000464709, Final residual = 3.32125e-08, No Iterations 1
GAMG:  Solving for p, Initial residual = 6.73208e-05, Final residual = 4.49914e-13, No Iterations 1
GAMG:  Solving for p, Initial residual = 4.48889e-13, Final residual = 4.48889e-13, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000171907, global = -0.000151647, cumulative = -0.0934224
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.16407e-07, Final residual = 1.16407e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.16407e-07, Final residual = 1.16407e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000171916, global = -0.000151647, cumulative = -0.0935741
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.16329e-07, Final residual = 1.16329e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.16329e-07, Final residual = 1.16329e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000171916, global = -0.000151647, cumulative = -0.0937257
rho max/min : 2 0.5
smoothSolver:  Solving for omega, Initial residual = 2.129e-06, Final residual = 2.07432e-10, No Iterations 1
smoothSolver:  Solving for k, Initial residual = 2.40993e-05, Final residual = 1.02225e-09, No Iterations 1
ExecutionTime = 70251.8 s  ClockTime = 94547 s

Courant Number mean: 0.000113739 max: 1
deltaT = 1.41781e-09
Time = 6.6266e-07

solidBodyMotionFunctions::rotatingMotion::transformation(): Time =  6.6266e-07 transformation: ((0 0 0) (0.999946 (0.0104089 0 0)))
AMI: Creating addressing and weights between 1900 source faces and 32076 target faces
AMI: Patch source sum(weights) min/max/average = 0.995413, 1, 0.999762
AMI: Patch target sum(weights) min/max/average = 0.473781, 1, 0.996806
AMI: Creating addressing and weights between 17748 source faces and 5456 target faces
AMI: Patch source sum(weights) min/max/average = 0.435284, 1.05167, 1.00015
AMI: Patch target sum(weights) min/max/average = 0.51984, 1.00247, 0.999844
AMI: Creating addressing and weights between 17839 source faces and 1957 target faces
AMI: Patch source sum(weights) min/max/average = 0.86998, 1, 0.999108
AMI: Patch target sum(weights) min/max/average = 0.991279, 1, 0.99992
GAMG:  Solving for pcorr, Initial residual = 1, Final residual = 0.00919969, No Iterations 54
GAMG:  Solving for pcorr, Initial residual = 1.21672e-05, Final residual = 1.21672e-05, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
rhoEqn max/min : 2.03418 0.471993
smoothSolver:  Solving for Ux, Initial residual = 3.16366e-05, Final residual = 2.11287e-09, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 0.00140093, Final residual = 1.12678e-07, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 0.00159565, Final residual = 1.25571e-07, No Iterations 1
smoothSolver:  Solving for h, Initial residual = 0.000461355, Final residual = 3.36557e-08, No Iterations 1
GAMG:  Solving for p, Initial residual = 6.71918e-05, Final residual = 6.20407e-13, No Iterations 1
GAMG:  Solving for p, Initial residual = 6.18972e-13, Final residual = 6.18972e-13, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000172306, global = -0.000152017, cumulative = -0.0938777
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.16604e-07, Final residual = 1.16604e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.16604e-07, Final residual = 1.16604e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000172314, global = -0.000152017, cumulative = -0.0940298
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.16525e-07, Final residual = 1.16525e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.16525e-07, Final residual = 1.16525e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000172314, global = -0.000152017, cumulative = -0.0941818
rho max/min : 2 0.5
smoothSolver:  Solving for omega, Initial residual = 2.12444e-06, Final residual = 9.55552e-11, No Iterations 1
smoothSolver:  Solving for k, Initial residual = 2.40609e-05, Final residual = 9.28125e-10, No Iterations 1
ExecutionTime = 70374.2 s  ClockTime = 94719 s

Courant Number mean: 0.000113719 max: 1
deltaT = 1.41781e-09
Time = 6.64078e-07

solidBodyMotionFunctions::rotatingMotion::transformation(): Time =  6.64078e-07 transformation: ((0 0 0) (0.999946 (0.0104311 0 0)))
AMI: Creating addressing and weights between 1900 source faces and 32076 target faces
AMI: Patch source sum(weights) min/max/average = 0.995413, 1, 0.999762
AMI: Patch target sum(weights) min/max/average = 0.47353, 1.00001, 0.996806
AMI: Creating addressing and weights between 17748 source faces and 5456 target faces
AMI: Patch source sum(weights) min/max/average = 0.431124, 1.05171, 1.00015
AMI: Patch target sum(weights) min/max/average = 0.519832, 1.00246, 0.999844
AMI: Creating addressing and weights between 17839 source faces and 1957 target faces
AMI: Patch source sum(weights) min/max/average = 0.86998, 1, 0.999108
AMI: Patch target sum(weights) min/max/average = 0.991279, 1, 0.99992
GAMG:  Solving for pcorr, Initial residual = 1, Final residual = 0.00988888, No Iterations 57
GAMG:  Solving for pcorr, Initial residual = 1.30742e-05, Final residual = 1.30742e-05, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
rhoEqn max/min : 2.02687 0.482841
smoothSolver:  Solving for Ux, Initial residual = 3.1612e-05, Final residual = 2.10315e-09, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 0.00139863, Final residual = 1.12206e-07, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 0.00159138, Final residual = 1.24932e-07, No Iterations 1
smoothSolver:  Solving for h, Initial residual = 0.000457716, Final residual = 3.34466e-08, No Iterations 1
GAMG:  Solving for p, Initial residual = 6.70692e-05, Final residual = 5.14521e-13, No Iterations 1
GAMG:  Solving for p, Initial residual = 5.13329e-13, Final residual = 5.13329e-13, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000172702, global = -0.000152384, cumulative = -0.0943342
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.16259e-07, Final residual = 1.16259e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.16259e-07, Final residual = 1.16259e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.00017271, global = -0.000152384, cumulative = -0.0944865
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.16181e-07, Final residual = 1.16181e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.16181e-07, Final residual = 1.16181e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.00017271, global = -0.000152384, cumulative = -0.0946389
rho max/min : 2 0.5
smoothSolver:  Solving for omega, Initial residual = 2.12412e-06, Final residual = 9.48272e-11, No Iterations 1
smoothSolver:  Solving for k, Initial residual = 2.40277e-05, Final residual = 9.26293e-10, No Iterations 1
ExecutionTime = 70511.2 s  ClockTime = 94911 s

Courant Number mean: 0.000113698 max: 1
deltaT = 1.4178e-09
Time = 6.65496e-07

solidBodyMotionFunctions::rotatingMotion::transformation(): Time =  6.65496e-07 transformation: ((0 0 0) (0.999945 (0.0104534 0 0)))
AMI: Creating addressing and weights between 1900 source faces and 32076 target faces
AMI: Patch source sum(weights) min/max/average = 0.995413, 1, 0.999762
AMI: Patch target sum(weights) min/max/average = 0.47328, 1, 0.996806
AMI: Creating addressing and weights between 17748 source faces and 5456 target faces
AMI: Patch source sum(weights) min/max/average = 0.447838, 1.05176, 1.00015
AMI: Patch target sum(weights) min/max/average = 0.519822, 1.00245, 0.99986
AMI: Creating addressing and weights between 17839 source faces and 1957 target faces
AMI: Patch source sum(weights) min/max/average = 0.86998, 1, 0.999108
AMI: Patch target sum(weights) min/max/average = 0.991279, 1, 0.99992
GAMG:  Solving for pcorr, Initial residual = 1, Final residual = 0.00924126, No Iterations 54
GAMG:  Solving for pcorr, Initial residual = 1.2222e-05, Final residual = 1.2222e-05, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
rhoEqn max/min : 2.03417 0.472107
smoothSolver:  Solving for Ux, Initial residual = 3.15871e-05, Final residual = 2.09785e-09, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 0.00139647, Final residual = 1.11942e-07, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 0.0015874, Final residual = 1.24392e-07, No Iterations 1
smoothSolver:  Solving for h, Initial residual = 0.000453908, Final residual = 3.31894e-08, No Iterations 1
GAMG:  Solving for p, Initial residual = 6.69419e-05, Final residual = 6.18263e-13, No Iterations 1
GAMG:  Solving for p, Initial residual = 6.16834e-13, Final residual = 6.16834e-13, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000173096, global = -0.000152751, cumulative = -0.0947917
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.15716e-07, Final residual = 1.15716e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.15716e-07, Final residual = 1.15716e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000173105, global = -0.000152751, cumulative = -0.0949444
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.15638e-07, Final residual = 1.15638e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.15638e-07, Final residual = 1.15638e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000173105, global = -0.000152751, cumulative = -0.0950972
rho max/min : 2 0.5
smoothSolver:  Solving for omega, Initial residual = 2.12485e-06, Final residual = 9.43144e-11, No Iterations 1
smoothSolver:  Solving for k, Initial residual = 2.39952e-05, Final residual = 9.24967e-10, No Iterations 1
ExecutionTime = 70649.8 s  ClockTime = 95106 s

Courant Number mean: 0.000113677 max: 1.00001
deltaT = 1.41779e-09
Time = 6.66913e-07

solidBodyMotionFunctions::rotatingMotion::transformation(): Time =  6.66913e-07 transformation: ((0 0 0) (0.999945 (0.0104757 0 0)))
AMI: Creating addressing and weights between 1900 source faces and 32076 target faces
AMI: Patch source sum(weights) min/max/average = 0.995413, 1, 0.999762
AMI: Patch target sum(weights) min/max/average = 0.473032, 1.00001, 0.996806
AMI: Creating addressing and weights between 17748 source faces and 5456 target faces
AMI: Patch source sum(weights) min/max/average = 0.447836, 1.0518, 1.00015
AMI: Patch target sum(weights) min/max/average = 0.51981, 1.00244, 0.99986
AMI: Creating addressing and weights between 17839 source faces and 1957 target faces
AMI: Patch source sum(weights) min/max/average = 0.86998, 1, 0.999108
AMI: Patch target sum(weights) min/max/average = 0.991279, 1, 0.99992
GAMG:  Solving for pcorr, Initial residual = 1, Final residual = 0.00988871, No Iterations 57
GAMG:  Solving for pcorr, Initial residual = 1.30738e-05, Final residual = 1.30738e-05, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
rhoEqn max/min : 2.02717 0.48285
smoothSolver:  Solving for Ux, Initial residual = 3.15639e-05, Final residual = 2.09028e-09, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 0.00139419, Final residual = 1.11562e-07, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 0.00158337, Final residual = 1.23881e-07, No Iterations 1
smoothSolver:  Solving for h, Initial residual = 0.000450021, Final residual = 3.2803e-08, No Iterations 1
GAMG:  Solving for p, Initial residual = 6.68107e-05, Final residual = 4.95164e-13, No Iterations 1
GAMG:  Solving for p, Initial residual = 4.94024e-13, Final residual = 4.94024e-13, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.00017349, global = -0.000153117, cumulative = -0.0952503
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.15139e-07, Final residual = 1.15139e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.15139e-07, Final residual = 1.15139e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000173498, global = -0.000153117, cumulative = -0.0954034
rho max/min : 2 0.5
GAMG:  Solving for p, Initial residual = 1.15061e-07, Final residual = 1.15061e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 1.15061e-07, Final residual = 1.15061e-07, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000173498, global = -0.000153117, cumulative = -0.0955565
rho max/min : 2 0.5
smoothSolver:  Solving for omega, Initial residual = 2.12539e-06, Final residual = 9.40374e-11, No Iterations 1
smoothSolver:  Solving for k, Initial residual = 2.39606e-05, Final residual = 9.23655e-10, No Iterations 1
ExecutionTime = 70803.7 s  ClockTime = 95324 s


Jetfire November 10, 2014 00:53

But Later, after a few iterations my simulation crashes showing this


Code:

[7] #0  Foam::error::printStack(Foam::Ostream&) in  "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[7] #1  Foam::sigFpe::sigHandler(int) in "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[7] #2  in "/lib/x86_64-linux-gnu/libc.so.6"
[7] #3  Foam::hePsiThermo<Foam::psiThermo,  Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie>  >, Foam::sensibleEnthalpy> > > >::calculate() in  "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
[7] #4  Foam::hePsiThermo<Foam::psiThermo,  Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie>  >, Foam::sensibleEnthalpy> > > >::correct() in  "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
[7] #5 
[7]  in "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/bin/rhoPimpleDyMFoam"
[7] #6  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
[7] #7 
[7]  in "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/bin/rhoPimpleDyMFoam"
[EAT-Standalone:13533] *** Process received signal ***
[EAT-Standalone:13533] Signal: Floating point exception (8)
[EAT-Standalone:13533] Signal code:  (-6)
[EAT-Standalone:13533] Failing at address: 0x3e8000034dd
[EAT-Standalone:13533] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x364a0) [0x7fc667b0b4a0]
[EAT-Standalone:13533] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x35) [0x7fc667b0b425]
[EAT-Standalone:13533] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x364a0) [0x7fc667b0b4a0]
[EAT-Standalone:13533] [ 3]  /home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so(_ZN4Foam11hePsiThermoINS_9psiThermoENS_11pureMixtureINS_19sutherlandTransportINS_7species6thermoINS_12hConstThermoINS_10perfectGasINS_6specieEEEEENS_16sensibleEnthalpyEEEEEEEE9calculateEv+0x2ab)  [0x7fc66d071f0b]
[EAT-Standalone:13533] [ 4]  /home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so(_ZN4Foam11hePsiThermoINS_9psiThermoENS_11pureMixtureINS_19sutherlandTransportINS_7species6thermoINS_12hConstThermoINS_10perfectGasINS_6specieEEEEENS_16sensibleEnthalpyEEEEEEEE7correctEv+0x32)  [0x7fc66d07f5f2]
[EAT-Standalone:13533] [ 5] rhoPimpleDyMFoam() [0x41f217]
[EAT-Standalone:13533] [ 6] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7fc667af676d]
[EAT-Standalone:13533] [ 7] rhoPimpleDyMFoam() [0x42660d]
[EAT-Standalone:13533] *** End of error message ***
--------------------------------------------------------------------------
mpirun noticed that process rank 7 with PID 13533 on node EAT-Standalone exited on signal 8 (Floating point exception).
--------------------------------------------------------------------------
[7] #0  Foam::error::printStack(Foam::Ostream&) in  "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[7] #1  Foam::sigFpe::sigHandler(int) in "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[7] #2  in "/lib/x86_64-linux-gnu/libc.so.6"
[7] #3  Foam::hePsiThermo<Foam::psiThermo,  Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie>  >, Foam::sensibleEnthalpy> > > >::calculate() in  "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
[7] #4  Foam::hePsiThermo<Foam::psiThermo,  Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie>  >, Foam::sensibleEnthalpy> > > >::correct() in  "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
[7] #5 
[7]  in "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/bin/rhoPimpleDyMFoam"
[7] #6  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
[7] #7 
[7]  in "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/bin/rhoPimpleDyMFoam"
[EAT-Standalone:13837] *** Process received signal ***
[EAT-Standalone:13837] Signal: Floating point exception (8)
[EAT-Standalone:13837] Signal code:  (-6)
[EAT-Standalone:13837] Failing at address: 0x3e80000360d
[EAT-Standalone:13837] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x364a0) [0x7fd517db24a0]
[EAT-Standalone:13837] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x35) [0x7fd517db2425]
[EAT-Standalone:13837] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x364a0) [0x7fd517db24a0]
[EAT-Standalone:13837] [ 3]  /home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so(_ZN4Foam11hePsiThermoINS_9psiThermoENS_11pureMixtureINS_19sutherlandTransportINS_7species6thermoINS_12hConstThermoINS_10perfectGasINS_6specieEEEEENS_16sensibleEnthalpyEEEEEEEE9calculateEv+0x2ab)  [0x7fd51d318f0b]
[EAT-Standalone:13837] [ 4]  /home/eatin/OpenFOAM/OpenFOAM-2.3.0/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so(_ZN4Foam11hePsiThermoINS_9psiThermoENS_11pureMixtureINS_19sutherlandTransportINS_7species6thermoINS_12hConstThermoINS_10perfectGasINS_6specieEEEEENS_16sensibleEnthalpyEEEEEEEE7correctEv+0x32)  [0x7fd51d3265f2]
[EAT-Standalone:13837] [ 5] rhoPimpleDyMFoam() [0x41f217]
[EAT-Standalone:13837] [ 6] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7fd517d9d76d]
[EAT-Standalone:13837] [ 7] rhoPimpleDyMFoam() [0x42660d]
[EAT-Standalone:13837] *** End of error message ***
--------------------------------------------------------------------------
mpirun noticed that process rank 7 with PID 13837 on node EAT-Standalone exited on signal 8 (Floating point exception).
--------------------------------------------------------------------------
[1]+  Exit 136                mpirun -np 8 rhoPimpleDyMFoam -parallel > log

Can you help me out on what caused this error.
I am unable to attach my output log file as it is exceeding max file size even after compressing it. I will mail it to you if you give me your mail id's.

Thanks

RodriguezFatz November 10, 2014 02:55

Did you set "default Gauss linear uncorrected"?
I would try to use the "uncorrected" just for the -omega- term. Or firstly better try "default Gauss linear limited 0.5".

Jetfire November 10, 2014 03:00

ok..

I will change it to Gauss Linear Limited 0.5
Please check post #40

RodriguezFatz November 10, 2014 03:03

Better ask Tobias about that stuff... I won't be any help.

Tobi November 10, 2014 03:54

Hi,

can you give the fvSchemes, fvSolutions and controlDict.

Jetfire November 10, 2014 03:58

1 Attachment(s)
Please check attachments

Tobi November 10, 2014 05:02

Thanks,


Try and use the following settings:

controlDict
Code:

deltaT    1e-8;
writeInterval  2e-08;
writePrecision 10;
maxCo 2;



fvSolutions

Code:

    "(rho|U|h)"
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance      1e-06;
        relTol          0.1;
    }

    "(rho|U|h)Final"
    {
        $U;
        relTol          0;
    }

    "(k|epsilon|omega)"
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance      1e-10;
        relTol          0.1;
    }
    "(k|epsilon|omega)Final"
    {
        $k;
        relTol          0;
    }

PIMPLE
{
        momentumPredictor  yes;
            transonic          no;
            nOuterCorrectors    50;
            nCorrectors        2;
            nNonOrthogonalCorrectors 1;
            turbOnFinalIterOnly false;

            rhoMin          rhoMin [ 1 -3 0 0 0 ] 0.1;
            rhoMax          rhoMax [ 1 -3 0 0 0 ] 2.5;
}

relaxationFactors
{
            fields
            {
                            p        0.3;
                            pFinal  1;
            }
            equations
            {
                        "(U|h|k|epsilon|omega)"  0.4;
                        "(U|h|k|epsilon|omega)Final" 1;
            }
}

fvSchemes
Code:

gradSchemes
{
    default        Gauss linear;
}

divSchemes
{
    default        none;

    div(phi,U)      Gauss upwind; //linearUpwind grad(U);
    div(phi,h)      Gauss upwind; //linearUpwind grad(h);
    div(phi,K)      Gauss linear;
    div(meshPhi,p)  Gauss linear;
    div(phi,k)      Gauss upwind;
    div(phi,omega) Gauss upwind;
    div((muEff*dev2(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
    default        none ;
    laplacian(rAUf,pcorr)      Gauss linear corrected;
    laplacian(muEff,U)          Gauss linear corrected;
    laplacian(alphaEff,h)      Gauss linear corrected;
    laplacian(rhorAUf,p)        Gauss linear corrected;

    laplacian(DepsilonEff,epsilon)      Gauss linear uncorrected;
    laplacian(DkEff,k)                  Gauss linear uncorrected;
    laplacian(DomegaEff,omega)          Gauss linear uncorrected;

}

What I want to say (mean no harm) but:

I feel very sad that you did not change your files like we mentioned. All advices we gave to you are useless if you do not take it into account. That makes me very sad and especially the imagination that some people offers their time to reading threads, checking out the cases and errors to give any advice to solve the problem is demotivating because if I spend time to a problem and give some advice and none of the advice is used and the thread starter always ask the same questions, its like »time wasted« ... especially in old topics like » using the PIMPLE alogithm :(

The old posts contained the following changes (that are now included in the three files):
  • I mentioned that you should have a look to the PIMPLE blog
  • I additionally mentioned that it would be nice if you change your solution solver because smoothSolver is not always the best choice. You find nice threads in this forum about this topic.
  • At least Philipp told you to have a look at the first timesteps to check out your solution and maybe change the mesh in that zones which makes trouble. But if I look to your controlDict, I think you never reached your write time and hence that I think you did not check it out or could not check it out.

Again this mean no harm to you :o but in some cases it makes me very very sad to investigate time for such problems if the hints are not used.

At least - now - I can imagine why there are too less support of advanced FOAM users due to the above mentioned things. :(


I hope you will »copy paste« or »modify« your files and give feedback.

vasava November 10, 2014 05:10

Just to confirm, your rotor is rotating with 300000 RPM right??

Tobi November 10, 2014 05:15

Quote:

Originally Posted by vasava (Post 518302)
Just to confirm, your rotor is rotating with 300000 RPM right??

For me I thought its 300 RPM due to the comma 300,000 -> for me 300 RPM, but maybe your are right. If this would be correct (300.000) then there are a few things to change... but never did simulations in that RPM range.

Jetfire November 10, 2014 05:28

Hi tobi,

I really dint mean to make you sad
I was implementing the changes to the best of my knowledge.
I have read about the PIMPLE ALGORITHM on your blog and tried to implement relaxation factors for variables but ended up getting this
Code:

--> FOAM FATAL ERROR:  previous iteration field IOobject: volScalarField p "/home/eatin/OpenFOAM/OpenFOAM-2.3.0/TurboCharger/Trail_run2/0"    not stored.  Use field.storePrevIter() at start of iteration.      From function GeometricField<Type, PatchField, GeoMesh>::prevIter() const    in file /home/eatin/OpenFOAM/OpenFOAM-2.3.0/src/OpenFOAM/lnInclude/GeometricField.C at line 863.  FOAM aborting
I figured out that i have to include this line in the solver based on replies from some other threads, but i do not know where exactly i have to include it.
Code:

field.storePrevIter( )

Philipp has suggested me to use Gauss linear uncorrected for the omega,As i had no knowledge about the other things in laplacian i changed to default Gauss linear uncorrected for the laplacian schemes. I had posted the output in post #41
then he suggested me to use default Gauss linear limited 0.5. please check post #43

I am using OpenFOAM for the first time and getting to know little about it day by day from experts like you through this forum and reading lot of threads. Please dont think i am not following your instructions, i am trying my level best to first understand your replies and implement them. I really thank you guys for helping me out and really appreaciate your efforts to patiently explain concepts to me.

Jetfire November 10, 2014 05:31

@vasava

Yes 300000 rpm

Tobi November 10, 2014 06:07

Hi,

as I told you its without mean on harm...
  1. you do not need to define all laplacian schemes, I just do it for you... you only set default to linear corrected and all other which should differ from that settings
    has an own entry
  2. I thought you are familiar with openFoam because you did not answered my question due to that topic
  3. If you apply the changes to the rhoPimpleDyMFoam tutorial everything is working fine, therefor it should work for your case too (you use rhoPimpleDyMFoam, arent you?)
  4. Is your case now working with my mentioned changes?
  5. Please start with deltaT = 1e-10;
  6. nOuterCorrectors = 100;
  7. start your case with rhoPimpleDyMFoam > log 2>&1
  8. or in parallel mpirun -np x rhoPimpleDyMFoam -parallel > log 2>&1
  9. Upload your log file


  • I am sorry but my browser did not showed the posts from 42 - 45!!! :(
  • Now I get the point why you change it to limited 0.5
  • The residual control should work, what did you insert that this error occured?
  • If you have problems you have to tell it » I can not check what you did without information

Jetfire November 10, 2014 06:24

Hi tobi,

Ya have modified the files as you suggested, changed the timStep to 1e-10 and running the simulation. Lot of pimple iterations per time step.Not even completed the first timeStep.

Will update you soon with the output.


Can you please check the output i got with the previous settings , they are here

http://www.cfd-online.com/Forums/ope...dymfoam-3.html

Post #41 and #42. Is the error because of my thermoPhysicalProperties ?? please confirm

Code:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                |                                                |
| \\      /  F ield        | OpenFOAM: The Open Source CFD Toolbox          |
|  \\    /  O peration    | Version:  2.3.0                                |
|  \\  /    A nd          | Web:      www.OpenFOAM.org                      |
|    \\/    M anipulation  |                                                |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version    2.0;
    format      ascii;
    class      dictionary;
    location    "constant";
    object      thermophysicalProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

thermoType
{
    type            hePsiThermo;
    mixture        pureMixture;
    transport      sutherland;
    thermo          hConst;
    equationOfState perfectGas;
    specie          specie;
    energy          sensibleEnthalpy;
}

mixture
{
    specie
    {
        nMoles      1;  // No. of moles
        molWeight  28.96; // Molecular weight of air
    }
    thermodynamics
    {
        Cp          1.0063e+3; // specific heat
        Hf          2.544e+06; // heat of fusion calculated using h=2501+1.84t where t=25 0C
    }
    transport
    {
      // mu        1.844e-05; // dynamic viscosity
      // Pr        0.7;  // prandtl number

        As              1.458e-06;  //sutherland coeffecient
        Ts              110.4;  //sutherland temperature
    }
}


// ************************************************************************* //


Jetfire November 10, 2014 06:42

Few clarifications

1. Should i increase my timeStep to 1e-09 after few iterations , this was calculated for courant no. 1? or 1e-10 is fine

2. Lot of pimple iterations per timeStep , taking high computational time , is this alright or shall i decrease the nOuterCorrectors ? ( Not even 1 timeStep completed yet :( )

3. Yes , I am using rhoPimpleDyMFoam and have implemented this change in the code mentioned here http://www.openfoam.org/mantisbt/view.php?id=909
to include the mesh motion. The term was missing before.

Tobi November 10, 2014 07:08

Hi,

due to the output I think its your thermodynamic model. You divide through zero (floating point exeption). Problem is that I dont know when this error occur but I think befor calculating the enthalpy h. Then you have problems with the thermodynamic class but I think in your case its more due to some instability problems of your solution.

So just use my mentioned modifications and have a look if everything is working. Use pyFoam for that (if you do not know it, it would be nice to check it out). Especially pyFoamPlotWatcher.py...

Tobi November 10, 2014 07:23

Quote:

Originally Posted by Jetfire (Post 518317)
Few clarifications

1. Should i increase my timeStep to 1e-09 after few iterations , this was calculated for courant no. 1? or 1e-10 is fine

No its automatically updated till you reach Co = 2.
Quote:

2. Lot of pimple iterations per timeStep , taking high computational time , is this alright or shall i decrease the nOuterCorrectors ? ( Not even 1 timeStep completed yet :( )
That is the sence of PIMPLE, merged PISO - SIMPLE. In the PIMPLE Loop you underrelax your solution (especially for stiff systems). After you reached your residualControl it will leave the LOOP and go to the next time step. The advantage is,
  • stability
  • bigger time steps


But I forgot something. The fvSolution file should look like that:
Code:

PIMPLE
{
    momentumPredictor  yes;
    transonic          no;
    nOuterCorrectors    100;
    nCorrectors        2;
    nNonOrthogonalCorrectors 1;
    turbOnFinalIterOnly false;

    rhoMin          rhoMin [ 1 -3 0 0 0 ] 0.1;
    rhoMax        rhoMax [ 1 -3 0 0 0 ] 2.5;

    residualControl   
    {       
            "(U|k|omega)"
            {
                      tolerance  1e-5;
                    relTol    0;
            }

              p
            {
                tolerance  1e-4;
                      relTol    0;   
              }   
    }

}

For you, » its also in my blog «

Now you underrelax the equations or matrixes and be much more stable. You use this relaxation factors till you reach your residual control criterions for each variable you set and the last iteration is with no relaxation factors (factors = 1). Normally the first time step will not converge if you have a complex problem but after a few time steps your Pimple loop can decrease from 200 loops to 12 loops. And you will get bigger timesteps and stable simulation. Thats the reason why PIMPLE is better than PISO if you want to have a look at bigger time steps.

If you set nOuterCorrections to 1 then you have PISO mode. Therefor maxCo should be set to 0.1 - 0.7 (depend on your case) and you are not allowed to underrelax anymore. If you use PISO your dT is something around 1e-5 to 1e-8 (depend on case and problem). For PIMPLE you can get much bigger timesteps. One iteration is more expensive but you go on in time faster.

Hope its clear now.

vasava November 11, 2014 03:16

@Tobi: Are rhoMin and rhoMax the value of minimum and maximum density from rhoCoeffs function respectively??

Jetfire November 11, 2014 03:30

Hi ,

So far the simulation is running well, it has reached to 8.5e-08 s.
I have included the residual control and the pimple is getting converged for 35 iterations each time step.

:)

Tobi November 11, 2014 04:36

Quote:

Originally Posted by Jetfire (Post 518473)
Hi ,

So far the simulation is running well, it has reached to 8.5e-08 s.
I have included the residual control and the pimple is getting converged for 35 iterations each time step.

:)

Very nice... like I told you ...
Now you have to analyse your output. To fasten up the simulation you have several options now:

  • increasing/decreasing nCorrectors, depend on your pressure eqn. maybe if you increase it to 3 you will leave the PIMPLE loop after 8 iterations - you have to play around
  • Change the relaxation factors (after a while it could be possible to increase it)
  • Befor starting a simulation you can renumber your mesh (my college gained 24% faster calculation compared with unrenumbered mesh)
  • Decompose your mesh that the faces between the processors are weighted. It makes no sence to have processors which share 10 faces with other processors.
    (scotch is not always the best)
Example:
One calculation needed 3 weeks with 18 cores, with correct decomposing and 10 cores it took me 4 days less

  • But be aware that you are sure that your residual control is well defined. Maybe the tolerance for p = 1e-4 is not sufficient or for k, omega, and U.
  • Also be sure to have turbOnFinalIterOnly » false (due to accuracy)
  • Also check the iterations of your equations. If k, epsilon are 0 maybe it is better to solve these equations till 1e-12...


Quote:

Originally Posted by vasava
@Tobi: Are rhoMin and rhoMax the value of minimum and maximum density from rhoCoeffs function respectively??


No. In the pEqn.H the solver calculates your density with your thermodynamic model. After that you bound your density with the values you insert in your fvSolution. That is helpful if you know that the density range of your fluid should be between 0.8 and 1 (or other values). If the thermodynamic calculates 0.001 and 3 in some cells it will be cutted and set to the values you set. That is very helpful if there are only some cells which give unphysical results. It stabilizes your solution BUT you should always check the output cutting is unphysical too. So if you set rhoMin to 0.5 and the solver calculate rhoMin = 0.43, you should decrease your rhoMin because 0.43 seems to be correct.

  • in this case here, jetfire just copy pasted the values out of a tutorial, but in his case it would be possible (due to pressure, temperature, velocity » 300.000 rpms) to get lower or higher densities like 0.5 and 2. Therefor I just setted some other values. You have to decide which values should be good.

    Example
    I am using and developing the flamelet solver (combustion model) and know that in my combustion the density only could be between 0.23 and 1.8. Therefor I change all cells which are not within these interval to this values.

    - its just an example because it will never happen in that solver :D

RodriguezFatz November 11, 2014 04:39

Hey jetfire, maybe we can speed up this a little. If you want that,
1) post some log output (one time step is enough)
2) how do you decompose?
3) post your current solver settings (fvSolution)

Tobi November 11, 2014 04:58

Quote:

Originally Posted by Jetfire (Post 518251)
Hi,
Sorry for the late reply , i was not at the work station

for the rhomin/max , with reference to the air properties at atmospheric pressure in the link http://www.engineeringtoolbox.com/ai...ies-d_156.html
I think my rhomin/max should not exceed the limits 0.524/2.793. But looking at the output there are timeSteps deviating from this for example.
Code:

CALCULATED density
rhoEqn max/min : 2.15688 0.182153 . .
GAMG:  Solving for p, Initial residual = 1.49854e-09, Final residual = 1.49854e-09, No Iterations 0 
ALL CELLS WHICH ARE NOT WITHIN THE DENSITY INTERVAL THAT YOU SET ARE BOUNDED AND THEN:
rho max/min : 2 0.5

Why is this happening ? any idea.

Please notice that in 300.000 rpm your pressure is not 1bar ...
The density changes due to pressure too! Can you check which pressure you will have in between your blades? I dont know which model you are using but the ideal gas rule is:

p \cdot V = m \cdot R_s \cdot T

\rho = \frac{m}{V}
means its proportional to

\rho \sim \frac{p}{T}
  • p = konst, and T increase --> rho decrease (like your table) and vice versa
  • p increase and T constant --> rho increase and vice versa
  • p and T not constant - depend on the ratio


As I expect, your rotor gives a high partial vacuum -> very small densities!
That is the reason (in my opinion) why your density is in that range. Therefor you should decrease your rhoMin to 0.1 or whatever.

vasava November 11, 2014 05:02

@Tobi: Thanks for the clarification.

Jetfire November 11, 2014 05:24

@Tobi,


Thanks for the tips to speeden up my simulation, I will try implementing them and let you know the results.

Can you message me your email id , i will send my output log file to you. Cannot post it here as it is exceeding max file size.

Tobi November 11, 2014 05:29

Quote:

Originally Posted by RodriguezFatz (Post 518485)
Hey jetfire, maybe we can speed up this a little. If you want that,
1) post some log output (one time step is enough)
2) how do you decompose?
3) post your current solver settings (fvSolution)

Its sufficient if you post only the last time step with all pimple loops like Philipp told. As you see we both had the same thoughts :)

Jetfire November 11, 2014 05:36

1 Attachment(s)
Quote:

Originally Posted by RodriguezFatz (Post 518485)
Hey jetfire, maybe we can speed up this a little. If you want that,
1) post some log output (one time step is enough)
2) how do you decompose?
3) post your current solver settings (fvSolution)


1. Please find the output for 2 timeSteps in attachments

2. I am using hierarchical decomposition with 8 cores.
Code:

numberOfSubdomains 8;

method          hierarchical;

hierarchicalCoeffs
{
    n              (2 2 2);
    delta          0.001;
    order          xyz;
}

3. FvSolution
Code:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                |                                                |
| \\      /  F ield        | OpenFOAM: The Open Source CFD Toolbox          |
|  \\    /  O peration    | Version:  2.3.0                                |
|  \\  /    A nd          | Web:      www.OpenFOAM.org                      |
|    \\/    M anipulation  |                                                |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version    2.0;
    format      ascii;
    class      dictionary;
    location    "system";
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p
    {
        solver          GAMG;
        smoother        GaussSeidel;
        cacheAgglomeration on;
        agglomerator    faceAreaPair;
        nCellsInCoarsestLevel 100;
        mergeLevels      1;
        tolerance      1e-06;
        relTol          0.01;
    }

    pFinal
    {
        $p;
        relTol          0;
    }

    pcorr
    {
        $p;
        tolerance      1e-2;
        relTol          0;
    }

    "(rho|U|h)"
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance      1e-06;
        relTol          0.1;
    }

    "(rho|U|h)Final"
    {
        $U;
        relTol          0;
    }

    "(k|epsilon|omega)"
    {
    solver        PBiCG;
    preconditioner    DILU;
    tolerance    1e-10;
    relTol        0.1;
    }

    "(k|epsilon|omega)Final"
    {
    $k;
    relTol        0;
    }

}

PIMPLE
{
    momentumPredictor  yes;
    transonic          no;
    nOuterCorrectors    100;
    nCorrectors        2;
    nNonOrthogonalCorrectors 1;
    turbOnFinalIterOnly        false;

    rhoMin          rhoMin [ 1 -3 0 0 0 ] 0.1;
    rhoMax          rhoMax [ 1 -3 0 0 0 ] 2.5;

    residualControl
    {
        "(U|k|omega)"
        {
            tolerance 1e-05;
            relTol          0;
                }

        p
                {
            tolerance 1e-04;
            relTol          0;
                }
    }
}

relaxationFactors
{
    fields
    {
    p    0.3;
    pFinal    1;
    }
    equations
    {
      "(U|h|k|epsilon|omega)"        0.4;
      "(U|h|k|epsilon|omega)Final"      1;
    }
}


// ************************************************************************* //


Tobi November 11, 2014 05:40

Quote:

Originally Posted by Jetfire (Post 518504)

2. I am using hierarchical decomposition with 8 cores.
Code:

numberOfSubdomains 8;

method          hierarchical;

hierarchicalCoeffs
{
    n              (2 2 2);
    delta          0.001;
    order          xyz;
}


That is not useful.
Please show us the output of your decomposition:
Code:

decomposePar > log
In your case, copy paste your project, decompose it again, store the output and publish it. After that you can remove your copy folder again.

fvSolution:
Code:

tolerance for U|h|rho -> 1e-9;
relTol 0.05;

nCorrectors = 1

residual control p-> 1e-5;

Was mich aber grad etwas stört ist deine Massenerhaltung:
Code:

time step continuity errors : sum local = 4.538409924e-06, global = -4.522927178e-06, cumulative = -0.002405985855
How many time steps did you calculate since now?
Please check your logfile with pyFoam (pyFoamPlotWatcher).

Additionally you can check your meshCourantNo if you insert "checkMeshCourantNo true" into the PIMPLE directory of your fvSolution. I think it is possible to increase your maxCo no to 3.

Jetfire November 11, 2014 05:42

I have the output of decomposePar on my terminal , here it is
Code:

/*---------------------------------------------------------------------------*\
| =========                |                                                |
| \\      /  F ield        | OpenFOAM: The Open Source CFD Toolbox          |
|  \\    /  O peration    | Version:  2.3.0                                |
|  \\  /    A nd          | Web:      www.OpenFOAM.org                      |
|    \\/    M anipulation  |                                                |
\*---------------------------------------------------------------------------*/
Build  : 2.3.0-f5222ca19ce6
Exec  : decomposePar
Date  : Nov 10 2014
Time  : 16:45:40
Host  : "EAT-Standalone"
PID    : 8606
Case  : /home/eatin/OpenFOAM/eatin-2.3.0/run/tutorials/TurboCharger/Trial_run2
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time



Decomposing mesh region0

Create mesh

Calculating distribution of cells
Selecting decompositionMethod hierarchical

Finished decomposition in 4.13 s

Calculating original mesh data

Distributing cells to processors

Distributing faces to processors

Distributing points to processors

Constructing processor meshes

Processor 0
    Number of cells = 828661
    Number of faces shared with processor 1 = 24114
    Number of faces shared with processor 2 = 10498
    Number of faces shared with processor 4 = 10485
    Number of processor patches = 3
    Number of processor faces = 45097
    Number of boundary faces = 67775

Processor 1
    Number of cells = 828661
    Number of faces shared with processor 0 = 24114
    Number of faces shared with processor 2 = 1298
    Number of faces shared with processor 3 = 6458
    Number of faces shared with processor 4 = 1879
    Number of faces shared with processor 5 = 6472
    Number of processor patches = 5
    Number of processor faces = 40221
    Number of boundary faces = 80623

Processor 2
    Number of cells = 828661
    Number of faces shared with processor 0 = 10498
    Number of faces shared with processor 1 = 1298
    Number of faces shared with processor 3 = 17656
    Number of faces shared with processor 4 = 4197
    Number of faces shared with processor 6 = 12647
    Number of faces shared with processor 7 = 715
    Number of processor patches = 6
    Number of processor faces = 47011
    Number of boundary faces = 62623

Processor 3
    Number of cells = 828661
    Number of faces shared with processor 1 = 6458
    Number of faces shared with processor 2 = 17656
    Number of faces shared with processor 7 = 6219
    Number of processor patches = 3
    Number of processor faces = 30333
    Number of boundary faces = 72641

Processor 4
    Number of cells = 828661
    Number of faces shared with processor 0 = 10485
    Number of faces shared with processor 1 = 1879
    Number of faces shared with processor 2 = 4197
    Number of faces shared with processor 5 = 15088
    Number of faces shared with processor 6 = 13676
    Number of processor patches = 5
    Number of processor faces = 45325
    Number of boundary faces = 81249

Processor 5
    Number of cells = 828661
    Number of faces shared with processor 1 = 6472
    Number of faces shared with processor 4 = 15088
    Number of faces shared with processor 6 = 2022
    Number of faces shared with processor 7 = 6375
    Number of processor patches = 4
    Number of processor faces = 29957
    Number of boundary faces = 78931

Processor 6
    Number of cells = 828661
    Number of faces shared with processor 2 = 12647
    Number of faces shared with processor 4 = 13676
    Number of faces shared with processor 5 = 2022
    Number of faces shared with processor 7 = 16593
    Number of processor patches = 4
    Number of processor faces = 44938
    Number of boundary faces = 70372

Processor 7
    Number of cells = 828661
    Number of faces shared with processor 2 = 715
    Number of faces shared with processor 3 = 6219
    Number of faces shared with processor 5 = 6375
    Number of faces shared with processor 6 = 16593
    Number of processor patches = 4
    Number of processor faces = 29902
    Number of boundary faces = 75444

Number of processor faces = 156392
Max number of cells = 828661 (0% above average 828661)
Max number of processor patches = 6 (41.17647059% above average 4.25)
Max number of faces between processors = 47011 (20.2388869% above average 39098)

Time = 0

Processor 0: field transfer
Processor 1: field transfer
Processor 2: field transfer
Processor 3: field transfer
Processor 4: field transfer
Processor 5: field transfer
Processor 6: field transfer
Processor 7: field transfer

End.


Tobi November 11, 2014 05:53

Hi,

Code:

Processor 1
    Number of cells = 828661
    Number of faces shared with processor 0 = 24114
    Number of faces shared with processor 2 = 1298
    Number of faces shared with processor 3 = 6458
    Number of faces shared with processor 4 = 1879
    Number of faces shared with processor 5 = 6472
    Number of processor patches = 5
    Number of processor faces = 40221
    Number of boundary faces = 80623

Processor 2
    Number of cells = 828661
    Number of faces shared with processor 0 = 10498
    Number of faces shared with processor 1 = 1298
    Number of faces shared with processor 3 = 17656
    Number of faces shared with processor 4 = 4197
    Number of faces shared with processor 6 = 12647
    Number of faces shared with processor 7 = 715

    Number of processor patches = 6
    Number of processor faces = 47011
    Number of boundary faces = 62623


Processor 7
    Number of cells = 828661
    Number of faces shared with processor 2 = 715
    Number of faces shared with processor 3 = 6219
    Number of faces shared with processor 5 = 6375
    Number of faces shared with processor 6 = 16593
    Number of processor patches = 4
    Number of processor faces = 29902
    Number of boundary faces = 75444

That is not well decomposed. As you can See its not really weighted. Other strategy would be much better, decompose your case only in x direction (if x is the length of your your pump).

Additionally after decomposing, renumbering!

Jetfire November 11, 2014 06:03

@Tobi

Here is my complete domain

http://www.cfd-online.com/Forums/ope...tml#post515511

Since large no. of elements are there in all 3 directions i have given '(2 2 2)' to make it 8 cores. The similar decomposition method is used for Propeller tutorial which is similar to my case. Please see the domain and let me know if i have to change the decomposition approach or change the subdomains.

RodriguezFatz November 11, 2014 06:41

Jetfire, did you try to use some other decomposition method? I had a very simple pipe flow and thought it is a clever idea to use "simple" decomposition. It showed low number of shared faces and all that stuff, but for some reason it was slower than just using "scotch" without any additional settings. You can just try some different methods and write down the different execution times. It's worth it for such long simulations to try a bit at the beginning.

Just a general question: Why is every time step converged to insanity? I mean, do you really get different results for these kind of problems with 30 pimple loops compared to - let's say a 3 times smaller time step and PISO solver (thus 1 outer iteration per time step)? Your Courant number is close to "1" anyway, so for stability of PISO just a slightly smaller time step would be needed. All the LES guys use PISO... is this that much different from what you are doing?

Also: Why the first pressure corrector with 60 iterations? For me, this looks like something is going utterly wrong. I think each linear solver should not take more than just a few iterations. Maybe this is again due to your solver, but please can someone elaborate this?

RodriguezFatz November 11, 2014 06:48

Another point is: Did you try different settings for the GAMG solver? I did this for a case of mine and found out that playing with "mergeLevels" decreased the simulation time (in my case "2" was the best). Also changing the pre,post,finest sweeps settings changed a lot:
Code:

  "(p|pFinal)"
        {
                solver          GAMG;
                tolerance        1e-12;
                relTol          0.1;

                maxIter          100;

                smoother        GaussSeidel;

                nPreSweeps      1;
                nPostSweeps      1;
                nFinestSweeps    2;

                cacheAgglomeration true;

                nCellsInCoarsestLevel 400;
                agglomerator    faceAreaPair;
                mergeLevels      2;

        }

This was the best for me.

Tobi November 11, 2014 07:23

Quote:

Originally Posted by RodriguezFatz (Post 518520)
Just a general question: Why is every time step converged to insanity? I mean, do you really get different results for these kind of problems with 30 pimple loops compared to - let's say a 3 times smaller time step and PISO solver (thus 1 outer iteration per time step)? Your Courant number is close to "1" anyway, so for stability of PISO just a slightly smaller time step would be needed. All the LES guys use PISO... is this that much different from what you are doing?

I did not get the point. Co should be increase to 2 during simulation (if it is set in the controlDict), you also can set it to 3 or 4 to get bigger time steps (depend on your relax factors also). But why should he use PISO? It would be much more expensiv and maybe not stable.

Quote:

Also: Why the first pressure corrector with 60 iterations? For me, this looks like something is going utterly wrong. I think each linear solver should not take more than just a few iterations. Maybe this is again due to your solver, but please can someone elaborate this?
I dont know which time step iteration is used but at the beginning in such chases it could be normal. Sometimes I also get 100 iterations for the pressure equation. Depend on the system and I never had rpm 300.000.

If you get 1000 Iterations something is wrong.
In the pressure calculation (my experience) it could occur. But it also could be possible that the BC are wrong for that problem. However, I first should have a look at the calculation procedure in that solver but there is not time for that now.

Quote:

Since large no. of elements are there in all 3 directions i have given '(2 2 2)' to make it 8 cores. The similar decomposition method is used for Propeller tutorial which is similar to my case. Please see the domain and let me know if i have to change the decomposition approach or change the subdomains.
My hints to you:
  • move your mesh that the long pipe is colinear with the z-axis (transform points)
  • then use manuelDecomposition
  • If its to complex try using scotch and have a look to the meshes
@Philipp, here in our institute we get the best results with simple or hierarchical instead of scotch. The gain was round about 13% because scotch decomposed our mesh in a very strange way.

RodriguezFatz November 11, 2014 07:29

Quote:

Originally Posted by Tobi (Post 518525)
I did not get the point. Co should be increase to 2 during simulation (if it is set in the controlDict), you also can set it to 3 or 4 to get bigger time steps (depend on your relax factors also). But why should he use PISO? It would be much more expensiv and maybe not stable.

Ok, the point was: Even with Co=3 or 4 and like 25 outer iterations I don't see a reason to use PIMPLE. In such cases, one PIMPLE time step would be like 25 PISO time steps, right? So, if you can reduce the time step by a factor of - let's say 8 - to get a Co of 0.5 and use PISO, you still have less computational time to spend. And you have a much finer time resolution.

Or is this just a matter of initialization? Does the number of PIMPLE loops decrease drastically after a few time steps?

Tobi November 11, 2014 07:47

Quote:

Originally Posted by RodriguezFatz (Post 518527)
Ok, the point was: Even with Co=3 or 4 and like 25 outer iterations I don't see a reason to use PIMPLE. In such cases, one PIMPLE time step would be like 25 PISO time steps, right?

Is there a paper who say that 25 PISO steps = 1 PIMPLE loop (with 25 iterations). In my opinion its not true because you can not compare the algorithms directly.

Quote:

So, if you can reduce the time step by a factor of - let's say 8 - to get a Co of 0.5 and use PISO, you still have less computational time to spend. And you have a much finer time resolution.
You are right, the time resolution would be better. But you have to check what is necessary in your case. So lets say you want simulate 1s and your mesh is big and the system is very stiff you. Therefor you have to set Co to (lets say) 0.3 to be stable. Therefor you will get a dT = 1e-9 which is very bad in that case. Also if there is one cell which makes trouble, this cell would reduce the whole time step, maybe to 1e-11 till it will crash. With relaxation you can handle this better.

  • well you are right you are more accurate in time
  • But if you have some problem cells that will reduce the time to 1e-11 its bad.
Quote:

Or is this just a matter of initialization? Does the number of PIMPLE loops decrease drastically after a few time steps?
It is definitiv also an initialization and boundary problem. If the boundary are bad defined or wrong, all algorithm will blow up or crash. The outer iterations will decrease during time steps. Sometimes I have loops like 80 at the beginning and after a few timesteps I get 8 - 10 and my timestep is much bigger than PISO. The computational costs decrease and the linear system is stable due to under-relaxation.

If there would be no advantage of PIMPLE compared to PISO then nobody would use PIMPLE.

RodriguezFatz November 11, 2014 07:56

Quote:

Originally Posted by Tobi (Post 518525)
If there would be no advantage of PIMPLE compared to PISO then nobody would use PIMPLE.

I got the feeling that he doesn't use the advantage of PIMPLE if he iterates more often than the number of PISO steps he actually needs if he reduces the time step. This is just an educated guess, I never tryed it.

Tobi November 11, 2014 08:56

He also can try something like that:

  • nOuterCorrection 3;
  • nCorrections 2;
Then the first 2 iterations are relaxed and the last one is without relaxation. But this could give stability problems because its relativ similar to PISO then but with 2 relaxation iterations. I am not sure if this case is working without relaxation. He can also switch to PISO again but then he should use maxCo 0.1 - 0.7 but not 1.

I can not test the case because I do not have it (:

Tobi November 11, 2014 10:26

Question: are you using the boundary condition which you attached in this post: http://www.cfd-online.com/Forums/ope...tml#post516087

The reason why I ask is due to the U - file, if it is like that you have an error which could be the reason of the pcorr iteration.


Quote:

Originally Posted by RodriguezFatz (Post 518530)
I got the feeling that he doesn't use the advantage of PIMPLE if he iterates more often than the number of PISO steps he actually needs if he reduces the time step. This is just an educated guess, I never tryed it.

That could be possible. I will check if I find some papers about that.

Jetfire November 11, 2014 23:06

1 Attachment(s)
Hi,

Bad news , Simulation crashed showing the same error as posted earlier after few timeSteps. check the output in attachments


  • Is this problem related to my thermoPhysicalProperties ? should I change my thermoPhysical settings?

Jetfire November 11, 2014 23:12

1 Attachment(s)
Quote:

Originally Posted by Tobi (Post 518564)
Question: are you using the boundary condition which you attached in this post: http://www.cfd-online.com/Forums/ope...tml#post516087

The reason why I ask is due to the U - file, if it is like that you have an error which could be the reason of the pcorr iteration.




That could be possible. I will check if I find some papers about that.

@Tobi do not refer to those boundary conditions, those were from annular thermal mixer tutorial, I am attaching my final 0 folder for your reference, do let me know if you need any other details.


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