[Black-Pearl]

Hello Foamers,

I try to simulate the heattransfer from air to aluminium melt.

Because both regions are fluids.
My problem is, that the temperature of the hot air rises to much and the solver crashes.

(heater = hot air)

...
Adding to radiations

Selecting radiationModel none
Adding fvOptions

No finite volume options present

Region: luft_1 Courant Number mean: 5.6643852e-06 max: 5.9790732e-06
Region: luft_2 Courant Number mean: 5.5804684e-06 max: 5.9790732e-06
Region: alu Courant Number mean: 4.2805601e-06 max: 5.9790732e-06
Region: heater Courant Number mean: 3.3681765e-06 max: 3.4843206e-06
Region: deckel Diffusion Number mean: 2.6216803e-16 max: 4.3940875e-16
Region: wall Diffusion Number mean: 3.6396234e-16 max: 5.8570489e-16
Region: handdeckel Diffusion Number mean: 4.5676729e-08 max: 6.8332266e-08
Region: zwischenwand Diffusion Number mean: 2.8232898e-15 max: 5.1249199e-15
Region: zwischenwand_2 Diffusion Number mean: 2.8232898e-15 max: 5.1249199e-15
deltaT = 1.1111111
Region: luft_1 Courant Number mean: 0.62937613 max: 0.66434147
Region: luft_2 Courant Number mean: 0.62005204 max: 0.66434147
Region: alu Courant Number mean: 0.47561779 max: 0.66434147
Region: heater Courant Number mean: 0.37424184 max: 0.38714673
Region: deckel Diffusion Number mean: 2.9129781e-11 max: 4.8823194e-11
Region: wall Diffusion Number mean: 4.044026e-11 max: 6.5078321e-11
Region: handdeckel Diffusion Number mean: 0.0050751921 max: 0.007592474
Region: zwischenwand Diffusion Number mean: 3.1369887e-10 max: 5.6943555e-10
Region: zwischenwand_2 Diffusion Number mean: 3.1369887e-10 max: 5.6943555e-10
deltaT = 1.1111111
Time = 1.11111


Solving for fluid region luft_1
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 1.737572e-08, No Iterations 4
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 6.5281948e-08, No Iterations 4
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 2.9039288e-08, No Iterations 4
DILUPBiCG: Solving for h, Initial residual = 1, Final residual = 3.2020789e-09, No Iterations 5
Min/max T:300.24666 993.14169
GAMG: Solving for p_rgh, Initial residual = 0.56298287, Final residual = 0.0032868215, No Iterations 3
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (luft_1): sum local = 2.3892722, global = 1.4963068e-06, cumulative = 1.4963068e-06
GAMG: Solving for p_rgh, Initial residual = 0.35860088, Final residual = 4.732492e-08, No Iterations 16
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (luft_1): sum local = 4.2957906e-05, global = 5.4348928e-09, cumulative = 1.5017417e-06

Solving for fluid region luft_2
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 1.0511042e-09, No Iterations 4
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 8.6199339e-08, No Iterations 3
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 3.1357105e-08, No Iterations 3
DILUPBiCG: Solving for h, Initial residual = 1, Final residual = 5.8394195e-10, No Iterations 4
Min/max T:287.5932 973.05287
GAMG: Solving for p_rgh, Initial residual = 0.71514628, Final residual = 0.0044174618, No Iterations 4
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (luft_2): sum local = 4.6086846, global = 0.047848992, cumulative = 0.047848992
GAMG: Solving for p_rgh, Initial residual = 0.53521726, Final residual = 8.5766589e-08, No Iterations 19
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (luft_2): sum local = 0.00011735656, global = -5.2057022e-08, cumulative = 0.04784894

Solving for fluid region alu
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 5.1476407e-09, No Iterations 4
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 8.6190324e-09, No Iterations 4
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 2.6978468e-09, No Iterations 4
DILUPBiCG: Solving for h, Initial residual = 1, Final residual = 1.1888477e-09, No Iterations 7
Min/max T:971.4221 979.4297
GAMG: Solving for p_rgh, Initial residual = 0.96087844, Final residual = 0.0079759011, No Iterations 4
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (alu): sum local = 1.3946648, global = -9.5125042e-16, cumulative = -9.5125042e-16
GAMG: Solving for p_rgh, Initial residual = 0.91174318, Final residual = 4.1837808e-08, No Iterations 13
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors (alu): sum local = 6.1779247e-06, global = 1.2161781e-16, cumulative = -8.2963261e-16

Solving for fluid region heater
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 5.355734e-08, No Iterations 6
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 5.7924232e-09, No Iterations 6
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 1.6373432e-08, No Iterations 6
DILUPBiCG: Solving for h, Initial residual = 1, Final residual = 5.0288202e-08, No Iterations 7
Min/max T:-4.9069669e+09 8.7303124e+09
#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::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4 void Foam::divide<Foam::fvsPatchField>(Foam::FieldField <Foam::fvsPatchField, double>&, Foam::FieldField<Foam::fvsPatchField, double> const&, Foam::FieldField<Foam::fvsPatchField, double> const&) at ??:?
#5 Foam::tmp<Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> > Foam:perator/<Foam::fvsPatchField, Foam::surfaceMesh>(Foam::tmp<Foam::GeometricField< double, Foam::fvsPatchField, Foam::surfaceMesh> > const&, Foam::tmp<Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> > const&) at ??:?
#6 Foam::fv::EulerDdtScheme<Foam::Vector<double> >::fvcDdtPhiCorr(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#7
at ??:?
#8
at ??:?
#9 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#10
at ??:?
Floating point exception (core dumped

My boundary conditions for the temperature:

heater/Hot-air

T
dimensions [0 0 0 1 0 0 0];

internalField uniform 1173.15;

boundaryField
{
heater_to_wall
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 1173.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
heater_to_deckel
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 1173.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
heater_to_alu
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 1173.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
}

for the aluminium melt (=alu)

T
dimensions [0 0 0 1 0 0 0];

internalField uniform 973.15;

boundaryField
{
alu_to_wall
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 973.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
alu_to_zwischenwand_2
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 973.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
alu_to_zwischenwand
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 973.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
alu_to_luft_2
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 973.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
alu_to_luft_1
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 973.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
alu_to_heater
{
type compressible::turbulentTemperatureCoupledBaffleMix ed;
value uniform 973.15;
neighbourFieldName T;
kappa fluidThermo;
kappaName none;
}
}

the thermophysical Properties

for the heater/Hot air

thermoType
{
type heRhoThermo;
mixture pureMixture;
transport const;
thermo hConst;
equationOfState perfectGas;
specie specie;
energy sensibleEnthalpy;
}

mixture
{
specie
{
nMoles 1;
molWeight 28.9;
}
thermodynamics
{
Cp 1170;
Hf 0; //2.554e+06;
}
transport
{
mu 1.8e-05;
Pr 0.7395;
}
}

for the aluminium melt:

thermoType
{
type heRhoThermo;
mixture pureMixture;
transport const;
thermo hConst;
equationOfState rhoConst;
specie specie;
energy sensibleEnthalpy;
}

mixture
{
specie
{
nMoles 1;
molWeight 26.98;
}
equationOfState
{
rho 2400;

}
thermodynamics
{
Cp 1000;
Hf 0;
}
transport
{
mu 0.03552;
Pr 0.18;
}
}

I could not find my problem. Have everyone an idea???

Thank you very much.

Best regards,

Ceci

[wyldckat]

Greetings Cecily,

When in doubt, try working from a simpler case and then increase the complexity gradually. Here's a good starting example: http://openfoamwiki.net/index.php/Ge..._-_planeWall2D

Best regards,
Bruno