[quarkz]

Hi,

I am running a hypersonic (M = 5) flow simulation on a double cone, using rhoCentralFoam. Currently I'm running a low resolution case (y+ ~ 4000) with laminar flow. The simulation ended successfully and I got some meaningful result. However, I wanted to test running with RANS, specifically using k Epsilon and k Omega SST.

I tried to use a turbulence length scale of 0.075m (7.5% of my reference length) and Turbulence intensity of 0.05% and then generate the values according to: https://www.cfd-online.com/Tools/turbulence.php

However, the simulation crashes right from the start. Having no experience with turbulence simulation, I'm not sure what's wrong. I tried changing some parameters like using a smaller CFL no., changing the solver, preconditioner. But they didn't help.

Anyway, I've listed down areas which I should change. But can anyone guide me? As to which is the most important:

1. CFL no, delta t etc
2. grid size, y+
3. solver, preconditioner
4. boundary conditions
5. turbulence parameters

Thanks!

[quarkz]

Hi,

I am still looking for solutions. Btw, here's the output I got when it diverges:

Mean and max Courant Numbers = 0.0005026 0.08949
Flow time scale min/max = 1.117e-08, 5.577e-08
Time = 3e-08

diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUx, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUy, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal: Solving for rhoUz, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver: Solving for Ux, Initial residual = 0.001518, Final residual = 3.367e-17, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 0.003317, Final residual = 3.727e-17, No Iterations 2
smoothSolver: Solving for Uz, Initial residual = 0.003138, Final residual = 3.756e-17, No Iterations 2
diagonal: Solving for rhoE, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver: Solving for e, Initial residual = 3.86e-07, Final residual = 2.933e-15, No Iterations 2
[26] #0 Foam::error:rintStack(Foam::Ostream&) at ??:?
[26] #1 Foam::sigFpe::sigHandler(int) at ??:?
[26] #2 ? in "/lib/x86_64-linux-gnu/libc.so.6"
[26] #3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
[26] #4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:perator/<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<doub le, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
[26] #5 Foam::kOmegaSST<Foam::eddyViscosity<Foam::RASModel <Foam::EddyDiffusivity<Foam::ThermalDiffusivity<Fo am::CompressibleTurbulenceModel<Foam::fluidThermo> > > > >, Foam::EddyDiffusivity<Foam::ThermalDiffusivity<Foa m::CompressibleTurbulenceModel<Foam::fluidThermo> > > >::correct() at ??:?
[26] #6 ? in "/home/tsltaywb/OpenFOAM/OpenFOAM-4.1/platforms/linux64GccDPInt32Opt/bin/rhoCentralFoam"
[26] #7 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
[26] #8 [9] #0 Foam::error:rintStack(Foam::Ostream&)? in "/home/tsltaywb/OpenFOAM/OpenFOAM-4.1/platforms/linux64GccDPInt32Opt/bin/rhoCentralFoam"
[compute4:20184] *** Process received signal ***
[compute4:20184] Signal: Floating point exception (8)
[compute4:20184] Signal code: (-6)
[compute4:20184] Failing at address: 0x3ea00004ed8
[compute4:20184] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x357f0)[0x2ad6760c67f0]
[compute4:20184] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x9f)[0x2ad6760c677f]
[compute4:20184] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x357f0)[0x2ad6760c67f0]
[compute4:20184] [ 3] /home/tsltaywb/OpenFOAM/OpenFOAM-4.1/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZN4Foam6divideERNS_5FieldIdEERKNS_ 5UListIdEES6_+0x115)[0x2ad675132225]
[compute4:20184] [ 4] /home/tsltaywb/OpenFOAM/OpenFOAM-4.1/platforms/linux64GccDPInt32Opt/lib/libturbulenceModels.so(_ZN4FoamdvINS_12fvPatchFiel dENS_7volMeshEEENS_3tmpINS_14GeometricFieldIdT_T0_ EEEERKS8_RKS7_+0x23e)[0x2ad673cc6f0e]
[compute4:20184] [ 5] /home/tsltaywb/OpenFOAM/OpenFOAM-4.1/platforms/linux64GccDPInt32Opt/lib/libcompressibleTurbulenceModels.so(_ZN4Foam9kOmega SSTINS_13eddyViscosityINS_8RASModelINS_15EddyDiffu sivityINS_18ThermalDiffusivityINS_27CompressibleTu rbulenceModelINS_11fluidThermoEEEEEEEEEEES9_E7corr ectEv+0x484)[0x2ad67422bb64]
[compute4:20184] [ 6] rhoCentralFoam(+0x324d1)[0x557160da84d1]
[compute4:20184] [ 7] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf1)[0x2ad6760b13f1]
[compute4:20184] [ 8] rhoCentralFoam(+0x36c5a)[0x557160dacc5a]
[compute4:20184] *** End of error message ***
[23] #0 Foam::error:rintStack(Foam::Ostream&) at ??:?
[9] #1 Foam::sigFpe::sigHandler(int) at ??:?
[9] #2 ? at ??:?
[23] #1 Foam::sigFpe::sigHandler(int) in "/lib/x86_64-linux-gnu/libc.so.6"
[9] #3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&)[2] #0 Foam::error:rintStack(Foam::Ostream&) at ??:?
[23] #2 ? at ??:?
[9] #4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:perator/<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<doub le, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/lib/x86_64-linux-gnu/libc.so.6"
[23] #3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?