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k-Epsilon model for compressible air

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Old   June 7, 2021, 14:23
Default k-Epsilon model for compressible air
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Carlos
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Hello all,

I hope that you may help me. I am building a venturing nozzle based on the "Supersonic flow over a forward-facing step "([URL="https://www.openfoam.com/documentation/tutorial-guide/3-compressible-flow/3.2-supersonic-flow-over-a-forward-facing-step"]).

The code runs well for my geometry. I have added a sketch of my geometry and the names of the patches.

Now, I am trying to add a k-Epsilon turbulent model to account for turbulence. However, I am struggling a lot with this.

The case crushes after 4 time steps:



Courant Number mean: 0.00183398 max: 0.296916
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab: Solving for Ux, Initial residual = 0.848478, Final residual = 7.41534e-07, No Iterations 1000
DILUPBiCGStab: Solving for Uy, Initial residual = 0.905086, Final residual = 9.39327e-06, No Iterations 1000
DILUPBiCGStab: Solving for e, Initial residual = 0.357641, Final residual = 8.74872e-10, No Iterations 828
DILUPBiCGStab: Solving for p, Initial residual = 0.999241, Final residual = 1177.16, No Iterations 1000
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 199.308, global = 4.46821, cumulative = 4.46821
DILUPBiCGStab: Solving for p, Initial residual = 0.979981, Final residual = 7.17817e+07, No Iterations 1000
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 88132.4, global = -30178.3, cumulative = -30173.8
DILUPBiCGStab: Solving for epsilon, Initial residual = 1, Final residual = 9.78935e-06, No Iterations 1000
bounding epsilon, min: -6.89085e+36 max: 3.41706e+36 average: 4.37867e+32
DILUPBiCGStab: Solving for k, Initial residual = 0.999482, Final residual = 4.61607e-11, No Iterations 6
bounding k, min: -5.46211e+31 max: 6.0254e+29 average: -3.7871e+26
#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/lib64/libc.so.6"
#3 Foam::nutUSpaldingWallFunctionFvPatchScalarField:: calcUTau(Foam::Field<double> const&) const at ??:?
#4 Foam::nutUSpaldingWallFunctionFvPatchScalarField:: calcNut() const at ??:?
#5 Foam::nutWallFunctionFvPatchScalarField::updateCoe ffs() at ??:?
#6 Foam::fvPatchField<double>::evaluate(Foam::UPstrea m::commsTypes) at ??:?
#7 Foam::RASModels::kEpsilon<Foam::EddyDiffusivity<Fo am::ThermalDiffusivity<Foam::CompressibleTurbulenc eModel<Foam::fluidThermo> > > >::correctNut() at ??:?
#8 Foam::RASModels::kEpsilon<Foam::EddyDiffusivity<Fo am::ThermalDiffusivity<Foam::CompressibleTurbulenc eModel<Foam::fluidThermo> > > >::correct() at ??:?
#9 ? at ??:?
#10 __libc_start_main in "/lib64/libc.so.6"
#11 ? at ??:?
Floating point exception (core dumped)

I think that my problem is in the BC for the turbulence.

I have attached all the files in this message. I am wondering if someone could help me. I am not sure what I am doing wrong.

Last edited by Ricardo1992; June 9, 2021 at 10:51.
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compressible air, k-epsilon model, openfoam, turbulence


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