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Negative Initial Temperature in rhoCentralFoam |
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September 23, 2023, 13:17 |
Negative Initial Temperature in rhoCentralFoam
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#1 |
New Member
Singh
Join Date: Jul 2023
Posts: 7
Rep Power: 3 |
Hello experts,
I have been running a 3D simulation on a hemispherical blunt body of length 1 m with a spike attached in front also of 1 m in rhoCentralFoam. The free-stream conditions are: U = 2339.26 m/s / Mach 6.82 P = 101325 Pa T = 300 K mu = 0.011965 rho_inf = 1.176407 Re no. = 0.23 * 10^6 Other thermal properties like Cv are of standard air. Both the top wall and the bottom wall is supersonicFreestream. I am also using k-epsilon turbulence model. It is a fine structured mesh with a good quality. But when I try to run the simulation, it crashes with the error: Code:
Mean and max Courant Numbers = 0.00171279 0.543028 Time = 1e-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 = 0.999999, Final residual = 9.9914e-06, No Iterations 613 smoothSolver: Solving for Uy, Initial residual = 1, Final residual = 9.90744e-06, No Iterations 114 smoothSolver: Solving for Uz, Initial residual = 1, Final residual = 9.91186e-06, No Iterations 114 diagonal: Solving for rhoE, Initial residual = 0, Final residual = 0, No Iterations 0 smoothSolver: Solving for e, Initial residual = 6.68248e-05, Final residual = 9.6125e-06, No Iterations 1 --> FOAM FATAL ERROR: (openfoam-2212 patch=230110) Negative initial temperature T0: -21.4718 From Foam::scalar Foam::species::thermo<Thermo, Type>::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar) const) const [with Thermo = Foam::hConstThermo<Foam::perfectGas<Foam::specie> >; Type = Foam::sensibleInternalEnergy; Foam::scalar = double; Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>] in file ./src/thermophysicalModels/specie/lnInclude/thermoI.H at line 57. FOAM aborting Code:
limitT { type limitTemperature; min 100; max 1000; selectionMode all; } fvSchemes: Code:
fluxScheme Kurganov; ddtSchemes { default Euler; } gradSchemes { default Gauss linear; } divSchemes { default none; div(phi,U) Gauss limitedLinearV 1; div(phi,e) Gauss limitedLinear 1; div(phid,p) Gauss limitedLinear 1; div(phi,K) Gauss limitedLinear 1; div(phiv,p) Gauss limitedLinear 1; div(tauMC) Gauss linear; turbulence Gauss upwind; div(phi,k) $turbulence; div(phi,epsilon) $turbulence; div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear; } laplacianSchemes { default Gauss linear corrected; } interpolationSchemes { default linear; reconstruct(rho) vanLeer; reconstruct(U) vanLeerV; reconstruct(T) vanLeer; } snGradSchemes { default corrected; } Code:
solvers { "rho.*" { solver diagonal; } "p.*" { solver smoothSolver; smoother symGaussSeidel; tolerance 1e-08; relTol 0; } "(U|e|R).*" { $p; tolerance 1e-05; } "(k|epsilon).*" { $p; tolerance 1e-08; } } PIMPLE { nOuterCorrectors 2; nCorrectors 1; nNonOrthogonalCorrectors 0; } |
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September 25, 2023, 03:08 |
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#2 |
Senior Member
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1/ First, test sanity of the case set-up by running using lower inlet mass flow rates.
2/ Second, try lower mass flow rates as initial guess for higher mass flow rate. 3/ Third, I imagine then negative temperatures can re-appear. Check whether using a limiter on temperature allows to run higher inflow rates. See https://www.openfoam.com/documentati...mitFields.html 4/ Fourth, get in touch in case difficulties persist. |
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September 25, 2023, 03:55 |
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#3 | |
Senior Member
Join Date: Dec 2021
Posts: 235
Rep Power: 5 |
Quote:
I would also try to ramp up the velocity over a few seconds at the beginning of the run, instead of going full throttle instantly |
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September 28, 2023, 15:50 |
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#4 | |
New Member
Singh
Join Date: Jul 2023
Posts: 7
Rep Power: 3 |
Quote:
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February 10, 2024, 23:04 |
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#5 |
New Member
Join Date: Nov 2023
Posts: 18
Rep Power: 2 |
Hi, I'm working with the kOmegaSST model and am getting a similar issue. I've tried ramping the velocity but I still wind up with the same problem, have you been able to find a fix?
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