| samiam1000 |
May 4, 2012 05:53 |
continuity error
Dear All,
I am running chtMultiRegionSimpleFoam and I get a continuity error.
At the 3rd time step, in fact, I get this message:
Code:
Time = 3
Solving for fluid region internal_air
DILUPBiCG: Solving for Ux, Initial residual = 0.04808972, Final residual = 0.0007848449, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.05127225, Final residual = 0.0006552669, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.0729375, Final residual = 0.001066777, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 0.02877754, Final residual = 0.001333761, No Iterations 1
Min/max T:273 280.0333
GAMG: Solving for p_rgh, Initial residual = 0.7510464, Final residual = 0.00749785, No Iterations 12
time step continuity errors : sum local = 0.1550988, global = 1.846758e-16, cumulative = -2.644312e-07
Min/max rho:1.241297 1.277639
Solving for fluid region external_air
DILUPBiCG: Solving for Ux, Initial residual = 0.08944471, Final residual = 0.0008127495, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.05704025, Final residual = 0.0005949483, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.09658343, Final residual = 0.0007494813, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 0.4380229, Final residual = 0.005028673, No Iterations 1
Min/max T:297.621 298.3227
--> FOAM FATAL ERROR:
Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
Total flux : 1564.848
Specified mass inflow : 0.01700355
Specified mass outflow : 0.0167709
Adjustable mass outflow : 0
From function adjustPhi(surfaceScalarField& phi, const volVectorField& U,const volScalarField& p
in file cfdTools/general/adjustPhi/adjustPhi.C at line 118.
FOAM exiting
It suggests to check the BC on the U field. I think that mine are properly set:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format binary;
class volVectorField;
location "0";
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
wall-external_air-roof
{
type fixedValue;
value uniform (0 0 0);
}
wall-door-external_air
{
type fixedValue;
value uniform (0 0 0);
}
symmetry_1-external_air
{
type symmetryPlane;
}
symmetry_2-external_air
{
type symmetryPlane;
}
wall_back-external_air
{
type fixedValue;
value uniform (0 0 0);
}
wall_front
{
type fixedValue;
value uniform (0 0 0);
}
ceiling
{
type fixedValue;
value uniform (0 0 0);
}
floor-external_air
{
type fixedValue;
value uniform (0 0 0);
}
/*infinite_air_inlet
{
type fixedValue;
value uniform (0 0.05 0);
}
infinite_air_outlet
{
type fixedValue;
value uniform (0 0.05 0);
}*/
infinite_air_inlet
{
type flowRateInletVelocity;
flowRate constant 0.017;
value uniform (0 0 0);
}
infinite_air_outlet
{
type zeroGradient;
}
}
// ************************************************************************* //
The p file is the following:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format binary;
class volScalarField;
location "0";
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [1 -1 -2 0 0 0 0];
internalField uniform 100000;
boundaryField
{
wall-external_air-roof
{
type calculated;
value uniform 100000;
}
wall-door-external_air
{
type calculated;
value uniform 100000;
}
symmetry_1-external_air
{
type symmetryPlane;
}
symmetry_2-external_air
{
type symmetryPlane;
}
wall_back-external_air
{
type calculated;
value uniform 100000;
}
wall_front
{
type calculated;
value uniform 100000;
}
ceiling
{
type calculated;
value uniform 100000;
}
floor-external_air
{
type calculated;
value uniform 100000;
}
/*infinite_air_inlet
{
type calculated;
value uniform 100000;
}*/
infinite_air_inlet
{
type zeroGradient;
}
infinite_air_outlet
{
type fixedValue;
value uniform 100000;
}
}
// ************************************************************************* //
Thanks for any help,
Samuele |
