[lixinhai]

I've just met some troubles in using twophaseeulerfoam. It was crash after a few iterations. I want to know why the value of the Min(alpha.air) become negative？

Create time

Create mesh for time = 0


PIMPLE: no residual control data found. Calculations will employ 3 corrector loops


Reading g

Reading hRef
Creating twoPhaseSystem

Selecting thermodynamics package
{
type heRhoThermo;
mixture pureMixture;
transport const;
thermo hConst;
equationOfState perfectGas;
specie specie;
energy sensibleInternalEnergy;
}

Calculating face flux field phi.air
Selecting diameterModel for phase air: isothermal
Selecting turbulence model type LES
Selecting LES turbulence model Smagorinsky
Selecting LES delta type cubeRootVol
SmagorinskyCoeffs
{
Ce 1.048;
Ck 0.094;
}

Selecting thermodynamics package
{
type heRhoThermo;
mixture pureMixture;
transport const;
thermo hConst;
equationOfState perfectFluid;
specie specie;
energy sensibleInternalEnergy;
}

Calculating face flux field phi.water
Selecting diameterModel for phase water: constant
Selecting turbulence model type LES
Selecting LES turbulence model NicenoKEqn
Selecting LES delta type cubeRootVol
NicenoKEqnCoeffs
{
Ce 1.048;
Ck 0.094;
alphaInversion 0.3;
Cp 0.094;
Cmub 0.6;
}

Selecting default blending method: linear
Selecting aspectRatioModel for (air in water): constant
Selecting aspectRatioModel for (water in air): constant
Selecting dragModel for (air and water): segregated
Selecting swarmCorrection for (air and water): none
Selecting dragModel for (air in water): SchillerNaumann
Selecting swarmCorrection for (air in water): none
Selecting dragModel for (water in air): SchillerNaumann
Selecting swarmCorrection for (water in air): none
Selecting virtualMassModel for (air in water): constantCoefficient
Selecting virtualMassModel for (water in air): constantCoefficient
Selecting heatTransferModel for (air in water): RanzMarshall
Selecting heatTransferModel for (water in air): RanzMarshall
Calculating field g.h

Reading field p_rgh

Creating field dpdt

Creating field kinetic energy K

No MRF models present

No finite volume options present

Courant Number mean: 7.7598e-09 max: 5.87416
Max Ur Courant Number = 5.87416
Calculating field DDtU1 and DDtU2


Starting time loop

fieldAverage fieldAverage1:
Starting averaging at time 0

Courant Number mean: 7.7598e-09 max: 5.87416
Max Ur Courant Number = 5.87416
Time = 0.0001

PIMPLE: iteration 1
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 1.55196e-08 Min(alpha.air) = 0 Max(alpha.air) = 11.7483
Constructing momentum equations
smoothSolver: Solving for e.air, Initial residual = 1, Final residual = 9.96649e-09, No Iterations 52
smoothSolver: Solving for e.water, Initial residual = 0.000156734, Final residual = 0.000104913, No Iterations 1000
min T.air 288.637
min T.water 300
GAMG: Solving for p_rgh, Initial residual = 0.961306, Final residual = 9.18955e-09, No Iterations 64
PIMPLE: iteration 2
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 1.145e-07 Min(alpha.air) = 0 Max(alpha.air) = 52.5699
Constructing momentum equations
smoothSolver: Solving for e.air, Initial residual = 0.483324, Final residual = 9.39689e-09, No Iterations 190
smoothSolver: Solving for e.water, Initial residual = 0.999981, Final residual = 9.55165e-09, No Iterations 25
min T.air -636.587
min T.water 299.973
GAMG: Solving for p_rgh, Initial residual = 0.800368, Final residual = 9.36696e-09, No Iterations 59
PIMPLE: iteration 3
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.000124845 Min(alpha.air) = -350247 Max(alpha.air) = 337950
Constructing momentum equations
#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3 ? in "/lib/x86_64-linux-gnu/libm.so.6"
#4 pow in "/lib/x86_64-linux-gnu/libm.so.6"
#5 Foamw(Foam::Field<double>&, Foam::UList<double> const&, double const&) at ??:?
#6 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foamw<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::dimensioned<double> const&) at ??:?
#7 Foam::dragModels::SchillerNaumann::CdRe() const at ??:?
#8 Foam::dragModel::Ki() const at ??:?
#9 Foam::dragModel::K() const at ??:?
#10 Foam::BlendedInterfacialModel<Foam::dragModel>::K( ) const at ??:?
#11 Foam::twoPhaseSystem::Kd() const at ??:?
#12 ? at ??:?
#13 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#14 ? at ??:?

[wouter]

hello lixinhai,
try a smaller timestep your courant number should be less than 1.
To be able to help you more you need to read the first few posts on how to ask questions. You need to give more information.

Hope this helps
Wouter

[lixinhai]

Thank you for reply.
I've set the courant number less than 0.5 and the timeStep is modifiable,but the case is still crash after a few iterations.