problem in solving fluent3DMeshToFoam and understanding courant number

itachi · March 8, 2020, 20:34

i have used fluent3DMeshToFoam to create the mesh.

and changed the 0 directory as per the boundary conditions, there were no error in forming the mesh, while doing the postprocessing i got the error. The solver i used is icoFoam.i also tried to reduce the time step but no use the error is the same and i'm not sure how to use fluent3DMeshtoFoam this is my first time using the technique to input mesh from ansys Fluent and i got the error as follow

Create time

Create mesh for time = 0

PISO: Operating solver in PISO mode

Reading transportProperties

Reading field p

Reading field U

Reading/calculating face flux field phi

Starting time loop

Time = 0.25

Courant Number mean: 361.928 max: 24602.2
smoothSolver: Solving for Ux, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver: Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver: Solving for Uz, Initial residual = 1, Final residual = 0.00237241, No Iterations 1000
DICPCG: Solving for p, Initial residual = 1, Final residual = 0.0456688, No Iterations 49
time step continuity errors : sum local = 0.0505461, global = 5.83724e-05, cumulative = 5.83724e-05
DICPCG: Solving for p, Initial residual = 0.173228, Final residual = 8.70596e-07, No Iterations 124
time step continuity errors : sum local = 1.16594e-05, global = 4.54525e-08, cumulative = 5.84179e-05
ExecutionTime = 10.26 s ClockTime = 10 s

Time = 0.5

Courant Number mean: 161.446 max: 6644.71
smoothSolver: Solving for Ux, Initial residual = 0.632821, Final residual = 0.00946253, No Iterations 1000
smoothSolver: Solving for Uy, Initial residual = 0.630718, Final residual = 0.00359746, No Iterations 1000
smoothSolver: Solving for Uz, Initial residual = 0.356938, Final residual = 0.016253, No Iterations 1000
DICPCG: Solving for p, Initial residual = 0.968441, Final residual = 0.0431518, No Iterations 51
time step continuity errors : sum local = 3.95353, global = -0.0550776, cumulative = -0.0550191
DICPCG: Solving for p, Initial residual = 0.168988, Final residual = 9.30204e-07, No Iterations 126
time step continuity errors : sum local = 0.00133669, global = 8.39336e-06, cumulative = -0.0550107
ExecutionTime = 37.44 s ClockTime = 37 s

Time = 0.75

Courant Number mean: 734.944 max: 59448.1
smoothSolver: Solving for Ux, Initial residual = 0.626513, Final residual = 0.0591268, No Iterations 1000
smoothSolver: Solving for Uy, Initial residual = 0.624025, Final residual = 0.00527135, No Iterations 1000
smoothSolver: Solving for Uz, Initial residual = 0.635244, Final residual = 0.312497, No Iterations 1000
DICPCG: Solving for p, Initial residual = 0.981377, Final residual = 0.0478388, No Iterations 51
time step continuity errors : sum local = 727.937, global = 1.48593, cumulative = 1.43092
DICPCG: Solving for p, Initial residual = 0.171069, Final residual = 9.38289e-07, No Iterations 124
time step continuity errors : sum local = 0.260373, global = -0.00256976, cumulative = 1.42835
ExecutionTime = 66.68 s ClockTime = 67 s

Time = 1

Courant Number mean: 365109 max: 2.20086e+07
#0 Foam::error:

rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3 Foam::symGaussSeidelSmoother::smooth(Foam::word const&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::Field<double> const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, unsigned char, int) at ??:?
#4 Foam::symGaussSeidelSmoother::smooth(Foam::Field<d ouble>&, Foam::Field<double> const&, unsigned char, int) const at ??:?
#5 Foam::smoothSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
#6 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam"
#7 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam"
#8 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam"
#9 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam"
#10 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#11 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam"
Floating point exception (core dumped)

geth03 · May 28, 2020, 09:39

i don't think that your problem is related to fluent mesh or the executable.

did you execute checkMesh ?

What does it say?

March 8, 2020, 20:34	problem in solving fluent3DMeshToFoam and understanding courant number	#1
itachi New Member vedha Join Date: Mar 2020 Posts: 3 Rep Power: 6	i have used fluent3DMeshToFoam to create the mesh. and changed the 0 directory as per the boundary conditions, there were no error in forming the mesh, while doing the postprocessing i got the error. The solver i used is icoFoam.i also tried to reduce the time step but no use the error is the same and i'm not sure how to use fluent3DMeshtoFoam this is my first time using the technique to input mesh from ansys Fluent and i got the error as follow Create time Create mesh for time = 0 PISO: Operating solver in PISO mode Reading transportProperties Reading field p Reading field U Reading/calculating face flux field phi Starting time loop Time = 0.25 Courant Number mean: 361.928 max: 24602.2 smoothSolver: Solving for Ux, Initial residual = 0, Final residual = 0, No Iterations 0 smoothSolver: Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0 smoothSolver: Solving for Uz, Initial residual = 1, Final residual = 0.00237241, No Iterations 1000 DICPCG: Solving for p, Initial residual = 1, Final residual = 0.0456688, No Iterations 49 time step continuity errors : sum local = 0.0505461, global = 5.83724e-05, cumulative = 5.83724e-05 DICPCG: Solving for p, Initial residual = 0.173228, Final residual = 8.70596e-07, No Iterations 124 time step continuity errors : sum local = 1.16594e-05, global = 4.54525e-08, cumulative = 5.84179e-05 ExecutionTime = 10.26 s ClockTime = 10 s Time = 0.5 Courant Number mean: 161.446 max: 6644.71 smoothSolver: Solving for Ux, Initial residual = 0.632821, Final residual = 0.00946253, No Iterations 1000 smoothSolver: Solving for Uy, Initial residual = 0.630718, Final residual = 0.00359746, No Iterations 1000 smoothSolver: Solving for Uz, Initial residual = 0.356938, Final residual = 0.016253, No Iterations 1000 DICPCG: Solving for p, Initial residual = 0.968441, Final residual = 0.0431518, No Iterations 51 time step continuity errors : sum local = 3.95353, global = -0.0550776, cumulative = -0.0550191 DICPCG: Solving for p, Initial residual = 0.168988, Final residual = 9.30204e-07, No Iterations 126 time step continuity errors : sum local = 0.00133669, global = 8.39336e-06, cumulative = -0.0550107 ExecutionTime = 37.44 s ClockTime = 37 s Time = 0.75 Courant Number mean: 734.944 max: 59448.1 smoothSolver: Solving for Ux, Initial residual = 0.626513, Final residual = 0.0591268, No Iterations 1000 smoothSolver: Solving for Uy, Initial residual = 0.624025, Final residual = 0.00527135, No Iterations 1000 smoothSolver: Solving for Uz, Initial residual = 0.635244, Final residual = 0.312497, No Iterations 1000 DICPCG: Solving for p, Initial residual = 0.981377, Final residual = 0.0478388, No Iterations 51 time step continuity errors : sum local = 727.937, global = 1.48593, cumulative = 1.43092 DICPCG: Solving for p, Initial residual = 0.171069, Final residual = 9.38289e-07, No Iterations 124 time step continuity errors : sum local = 0.260373, global = -0.00256976, cumulative = 1.42835 ExecutionTime = 66.68 s ClockTime = 67 s Time = 1 Courant Number mean: 365109 max: 2.20086e+07 #0 Foam::error:rintStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 ? in "/lib/x86_64-linux-gnu/libc.so.6" #3 Foam::symGaussSeidelSmoother::smooth(Foam::word const&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::Field<double> const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, unsigned char, int) at ??:? #4 Foam::symGaussSeidelSmoother::smooth(Foam::Field<d ouble>&, Foam::Field<double> const&, unsigned char, int) const at ??:? #5 Foam::smoothSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:? #6 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam" #7 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam" #8 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam" #9 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam" #10 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #11 ? in "/opt/openfoam5/platforms/linux64GccDPInt32Opt/bin/icoFoam" Floating point exception (core dumped)

May 28, 2020, 09:39		#2
geth03 Senior Member Join Date: Dec 2019 Location: Cologne, Germany Posts: 355 Rep Power: 8	i don't think that your problem is related to fluent mesh or the executable. did you execute checkMesh ? What does it say?