CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM

Error when solving p_rgh

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 17, 2020, 08:12
Default Error when solving p_rgh
  #1
New Member
 
Roberto
Join Date: Mar 2020
Posts: 1
Rep Power: 0
bob94 is on a distinguished road
Hi everybody!!

I recently started using openfoam for a project I'm working on.
In particular, I need a simulation of the heat exchange within a certain configuration. I'm trying using snappyHexMesh for creating the geometry and chtMultiRegionFoam as solver.

In my configuration I have both solids and fluids (air and alcohol).

When I only use solids I don't get errors, but when I go to insert fluids I almost always get errors when solving p_rgh (sometimes reaching the limit of iterations, other times instead of an error message).

To better understand the case:
- all the elements are at the same initial temperature of 300K and the fluids are always at atmospheric pressure
- in the constant/piastra folder I inserted an fvOptions file which operates a cooling of 100W
- to create the air zone in which the object is immersed, I inserted in the blockMesh file:

Code:
blocks
(
    hex (0 1 2 3 4 5 6 7) air (24 24 24) simpleGrading (1 1 1)
);
- for all temperature boundary conditions I used "compressible :: turbulentTemperatureCoupledBaffleMixed" and for all other parameters I used the same as the examples contained in the tutorials folder
- this is the error message

Code:
 

Region: air Courant Number mean: 0 max: 0
Region: alcool Courant Number mean: 0 max: 0
Region: piastra Diffusion Number mean: 0.24015812 max: 15.787614
Region: plexi Diffusion Number mean: 2.8440192e-05 max: 0.0032209747
Region: portaProv Diffusion Number mean: 0.31275907 max: 55.450193
Region: provette Diffusion Number mean: 0.001463558 max: 0.034645969
Region: strutSup Diffusion Number mean: 3.3476429e-05 max: 0.0087347803
deltaT = 0.00018034211
Region: air Courant Number mean: 0 max: 0
Region: alcool Courant Number mean: 0 max: 0
Region: piastra Diffusion Number mean: 0.043310623 max: 2.8471716
Region: plexi Diffusion Number mean: 5.1289642e-06 max: 0.00058087736
Region: portaProv Diffusion Number mean: 0.056403631 max: 10.000005
Region: provette Diffusion Number mean: 0.00026394114 max: 0.0062481271
Region: strutSup Diffusion Number mean: 6.0372098e-06 max: 0.0015752487
deltaT = 0.00018034211
Time = 0.000180342


Solving for fluid region air
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for Ux, Initial residual = 1, Final residual = 1.9114871e-08, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 1, Final residual = 7.1856507e-06, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 1, Final residual = 6.4711786e-09, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.99995728, Final residual = 7.0966155e-09, No Iterations 1
Min/max T:300 300
GAMG:  Solving for p_rgh, Initial residual = 0.14514543, Final residual = 0.0061678691, No Iterations 3
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (air): sum local = 1.2365165e-07, global = -9.7712567e-15, cumulative = -9.7712567e-15
GAMG:  Solving for p_rgh, Initial residual = 0.055844559, Final residual = 9.396246e-06, No Iterations 14
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (air): sum local = 5.7911232e-09, global = -1.0337223e-14, cumulative = -2.010848e-14

Solving for fluid region alcool
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for Ux, Initial residual = 1, Final residual = 1.4596229e-09, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 1, Final residual = 5.7710647e-09, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 1, Final residual = 1.5093634e-09, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.99985907, Final residual = 1.8031898e-11, No Iterations 1
Min/max T:300 300
GAMG:  Solving for p_rgh, Initial residual = 0.55243556, Final residual = 0.025787617, No Iterations 2
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (alcool): sum local = 2.0166478e-06, global = -8.3913624e-17, cumulative = -8.3913624e-17
GAMG:  Solving for p_rgh, Initial residual = 0.89287755, Final residual = 7.5969844e-08, No Iterations 46
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (alcool): sum local = 1.8039473e-12, global = -8.4504244e-17, cumulative = -1.6841787e-16

Solving for solid region piastra
DICPBiCGStab:  Solving for h, Initial residual = 1, Final residual = 6.0143068e-08, No Iterations 2
Min/max T:299.99993 300

Solving for solid region plexi
DICPBiCGStab:  Solving for h, Initial residual = 0.99975072, Final residual = 6.5126532e-07, No Iterations 1
Min/max T:299.99993 300

Solving for solid region portaProv
DICPBiCGStab:  Solving for h, Initial residual = 0.99999982, Final residual = 2.2015852e-07, No Iterations 2
Min/max T:299.99995 300

Solving for solid region provette
DICPBiCGStab:  Solving for h, Initial residual = 0.5391564, Final residual = 1.5222689e-09, No Iterations 1
Min/max T:300 300

Solving for solid region strutSup
DICPBiCGStab:  Solving for h, Initial residual = 0.54077457, Final residual = 2.0182476e-07, No Iterations 1
Min/max T:300 300
ExecutionTime = 11.32 s  ClockTime = 12 s

Region: air Courant Number mean: 1.9084062e-05 max: 0.00064475353
Region: alcool Courant Number mean: 1.7760967e-06 max: 9.0264841e-05
Region: piastra Diffusion Number mean: 0.043310623 max: 2.8471716
Region: plexi Diffusion Number mean: 5.1289642e-06 max: 0.00058087736
Region: portaProv Diffusion Number mean: 0.056403631 max: 10.000005
Region: provette Diffusion Number mean: 0.00026394114 max: 0.0062481271
Region: strutSup Diffusion Number mean: 6.0372098e-06 max: 0.0015752487
deltaT = 0.00018034211
Time = 0.000360684


Solving for fluid region air
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for Ux, Initial residual = 0.33281853, Final residual = 1.1239572e-06, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.57572852, Final residual = 4.5837412e-06, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.33292171, Final residual = 1.7943607e-06, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.99969992, Final residual = 9.9372367e-06, No Iterations 1
Min/max T:299.99998 300.00004
GAMG:  Solving for p_rgh, Initial residual = 0.16911283, Final residual = 0.0067219104, No Iterations 3
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (air): sum local = 9.5467063e-08, global = 1.3920691e-14, cumulative = -6.1877887e-15
GAMG:  Solving for p_rgh, Initial residual = 0.054468682, Final residual = 9.8343803e-06, No Iterations 18
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (air): sum local = 9.925107e-09, global = 1.9805379e-14, cumulative = 1.361759e-14

Solving for fluid region alcool
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for Ux, Initial residual = 0.26438262, Final residual = 5.0872577e-10, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.45263081, Final residual = 1.3171118e-09, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.29110743, Final residual = 6.9864336e-10, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.99999579, Final residual = 1.4432334e-11, No Iterations 1
Min/max T:299.99999 300.00003
GAMG:  Solving for p_rgh, Initial residual = 0.80060153, Final residual = 0.032809275, No Iterations 1
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (alcool): sum local = 7.2218368e-08, global = -3.5140225e-17, cumulative = -2.0355809e-16
GAMG:  Solving for p_rgh, Initial residual = 0.18159713, Final residual = 7.5960323e-08, No Iterations 45
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (alcool): sum local = 7.3563896e-14, global = -3.5132298e-17, cumulative = -2.3869039e-16

Solving for solid region piastra
DICPBiCGStab:  Solving for h, Initial residual = 0.97629277, Final residual = 9.90723e-07, No Iterations 2
Min/max T:299.99986 299.99998

Solving for solid region plexi
DICPBiCGStab:  Solving for h, Initial residual = 0.24353392, Final residual = 1.5918876e-07, No Iterations 1
Min/max T:299.99986 300

Solving for solid region portaProv
DICPBiCGStab:  Solving for h, Initial residual = 0.34170052, Final residual = 7.388575e-08, No Iterations 2
Min/max T:299.99991 300

Solving for solid region provette
DICPBiCGStab:  Solving for h, Initial residual = 0.99992906, Final residual = 8.4265129e-10, No Iterations 1
Min/max T:299.99999 300.00002

Solving for solid region strutSup
DICPBiCGStab:  Solving for h, Initial residual = 0.97894798, Final residual = 2.9735002e-07, No Iterations 1
Min/max T:300 300
ExecutionTime = 13.76 s  ClockTime = 15 s

Region: air Courant Number mean: 2.9965953e-05 max: 0.0006902855
Region: alcool Courant Number mean: 1.2285228e-06 max: 4.9915036e-05
Region: piastra Diffusion Number mean: 0.043310623 max: 2.8471716
Region: plexi Diffusion Number mean: 5.1289642e-06 max: 0.00058087736
Region: portaProv Diffusion Number mean: 0.056403631 max: 10.000005
Region: provette Diffusion Number mean: 0.00026394114 max: 0.0062481271
Region: strutSup Diffusion Number mean: 6.0372098e-06 max: 0.0015752487
deltaT = 0.00018034211
Time = 0.000541026


Solving for fluid region air
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for Ux, Initial residual = 0.19702503, Final residual = 1.5808326e-07, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.23696084, Final residual = 1.7058751e-06, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.2371358, Final residual = 8.6132764e-07, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.98522741, Final residual = 5.5073739e-06, No Iterations 1
Min/max T:299.99983 300.0002
GAMG:  Solving for p_rgh, Initial residual = 0.33982312, Final residual = 0.019533347, No Iterations 2
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (air): sum local = 1.6954736e-07, global = -1.2716672e-14, cumulative = 9.0091772e-16
GAMG:  Solving for p_rgh, Initial residual = 0.10996116, Final residual = 8.5437486e-06, No Iterations 22
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (air): sum local = 1.1619869e-08, global = 6.9900636e-16, cumulative = 1.5999241e-15

Solving for fluid region alcool
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for Ux, Initial residual = 0.078586205, Final residual = 3.6182856e-10, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.15353674, Final residual = 9.7023274e-10, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.28874942, Final residual = 6.8418329e-10, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.75356235, Final residual = 1.8520723e-09, No Iterations 1
Min/max T:299.99971 300.00003
GAMG:  Solving for p_rgh, Initial residual = 0.17236852, Final residual = 0.011704416, No Iterations 1
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (alcool): sum local = 1.1639358e-08, global = -8.441821e-17, cumulative = -3.231086e-16
[3] #0  Foam::error::printStack(Foam::Ostream&) at ??:?
[3] #1  Foam::sigFpe::sigHandler(int) at ??:?
[3] #2  ? in /lib64/libc.so.6
[3] #3  Foam::scalarProduct<double, double>::type Foam::sumProd<double>(Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
[3] #4  Foam::PCG::scalarSolve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
[3] #5  Foam::GAMGSolver::solveCoarsestLevel(Foam::Field<double>&, Foam::Field<double> const&) const at ??:?
[3] #6  Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMatrix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const at ??:?
[3] #7  Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
[3] #8  Foam::fvMatrix<double>::solveSegregated(Foam::dictionary const&) at ??:?
[3] #9  Foam::fvMatrix<double>::solveSegregatedOrCoupled(Foam::dictionary const&) at ??:?
[3] #10  Foam::fvMesh::solve(Foam::fvMatrix<double>&, Foam::dictionary const&) const at ??:?
[3] #11  ? at ??:?
[3] #12  __libc_start_main in /lib64/libc.so.6
[3] #13  ? at ??:?
[e8c14275c37d:01576] *** Process received signal ***
[e8c14275c37d:01576] Signal: Floating point exception (8)
[e8c14275c37d:01576] Signal code:  (-6)
[e8c14275c37d:01576] Failing at address: 0x628
[e8c14275c37d:01576] [ 0] /lib64/libc.so.6(+0x35270)[0x7f8bbf62e270]
[e8c14275c37d:01576] [ 1] /lib64/libc.so.6(gsignal+0x37)[0x7f8bbf62e1f7]
[e8c14275c37d:01576] [ 2] /lib64/libc.so.6(+0x35270)[0x7f8bbf62e270]
[e8c14275c37d:01576] [ 3] /opt/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZN4Foam7sumProdIdEENS_13scalarProductIT_S2_E4typeERKNS_5UListIS2_EES8_+0x25)[0x7f8bc0b17cc5]
[e8c14275c37d:01576] [ 4] /opt/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZNK4Foam3PCG11scalarSolveERNS_5FieldIdEERKS2_h+0x9c5)[0x7f8bc096a675]
[e8c14275c37d:01576] [ 5] /opt/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZNK4Foam10GAMGSolver18solveCoarsestLevelERNS_5FieldIdEERKS2_+0x91)[0x7f8bc0988511]
[e8c14275c37d:01576] [ 6] /opt/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZNK4Foam10GAMGSolver6VcycleERKNS_7PtrListINS_9lduMatrix8smootherEEERNS_5FieldIdEERKS8_S9_S9_S9_S9_S9_RNS1_IS8_EESD_h+0x71e)[0x7f8bc098936e]
[e8c14275c37d:01576] [ 7] /opt/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZNK4Foam10GAMGSolver5solveERNS_5FieldIdEERKS2_h+0x5ea)[0x7f8bc098bb7a]
[e8c14275c37d:01576] [ 8] /opt/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib/libfiniteVolume.so(_ZN4Foam8fvMatrixIdE15solveSegregatedERKNS_10dictionaryE+0x11f)[0x7f8bc76d620f]
[e8c14275c37d:01576] [ 9] /opt/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib/libfiniteVolume.so(_ZN4Foam8fvMatrixIdE24solveSegregatedOrCoupledERKNS_10dictionaryE+0x27f)[0x7f8bc702b08f]
[e8c14275c37d:01576] [10] /opt/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib/libfiniteVolume.so(_ZNK4Foam6fvMesh5solveERNS_8fvMatrixIdEERKNS_10dictionaryE+0xf)[0x7f8bc6fed45f]
[e8c14275c37d:01576] [11] chtMultiRegionFoam[0x43a550]
[e8c14275c37d:01576] [12] /lib64/libc.so.6(__libc_start_main+0xf5)[0x7f8bbf61ac05]
[e8c14275c37d:01576] [13] chtMultiRegionFoam[0x440fa6]
[e8c14275c37d:01576] *** End of error message ***
--------------------------------------------------------------------------
mpirun noticed that process rank 3 with PID 1576 on node e8c14275c37d exited on signal 8 (Floating point exception).
- in many tests that I have done sometimes it happened that trying to solve in parallel instead of on a single processor I did not get errors

- I created the stl files through AutoCad and then imported / modified and exported them through blender

- I also tried to isolate the mesh with the subSet command (the test I did with solids only) but when I insert more fluids I get this error

My questions are therefore:
- am I using the right solver?
- what are the initial values ​​of p_rgh (for liquid and for gas), the boundary conditions and best solver in fvSolution?
- why sometimes I don't get errors if I run in parallel
P.S.
even if I finish the simulation very often I don't get what I expect (heat not transmitted inside a solid, strange pressure values ​​or temperature values ​​higher than 300K even if I only have cooling)
Attached Files
File Type: zip testNoSimple.zip (152.3 KB, 1 views)
bob94 is offline   Reply With Quote

Reply

Tags
chtmultiregionfoam, p_rgh

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
laplacianFoam with source term Herwig OpenFOAM Running, Solving & CFD 17 November 19, 2019 13:47
Segmentation fault when using reactingFOAM for Fluids Tommy Floessner OpenFOAM Running, Solving & CFD 4 April 22, 2018 12:30
chtMultiRegionSimpleFoam turbulent case Aditya Patil OpenFOAM Running, Solving & CFD 6 April 24, 2017 22:13
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 06:20
Unstabil Simulation with chtMultiRegionFoam mbay101 OpenFOAM Running, Solving & CFD 13 December 28, 2013 13:12


All times are GMT -4. The time now is 17:57.