[wayne14]

Hi everyone,

I am trying to solve a species transport problem in darcy flow. Both viscosity and density depend on the species concentrations.

The equations and my calculation procedure are attached.

My test case is a point leakage at the location (0,0,0). I will post the case and solver here.

Hope you can help me.

Regards,

Wayne

[wayne14]

This is the solver and the two test case.

In test case Exo72D2Q0, the source strength is set to 0.
In this case, the air should just pile up without any movement.
The boundary conditions for pressure p seems to be ok now as follows:

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 101.325e3;

boundaryField
{
    frontandback
    {
        type empty;
    }
    walls
    {
        type            zeroGradient;
    }

    up
    {
        type            fixedValue;
        value           uniform 101.325e3;

    }

    down
    {
       type groovyBC;

       variables "gradp=Rho*9.81;";
       gradientExpression "gradp";
       value uniform 101361.69921;
       fractionExpression "0";
    }
}

// ************************************************************************* //

[wayne14]

In test case Exo72D2, the source strength for CH4 is
Q Q [1 0 -1 0 0 0 0] 1.48e-5;// kg/s

This time the p still converge very fast, but the concentration (kg/kg) of CH4, 'TS2', would not converge below e-3
The concentration (kg/kg) of CH4 is shown in TS2.jpg and TS2 bigger.jpg.
The biggest problem is that TS2 does not meet the mass balance! Will someone be interested in helping me?

[wayne14]

It seems that the problem have been solved after I correct the boundary conditions. However, I still wish that you can comment on my solver so that I can develop a better one in the future.

[kostnermo]

Hi Yan,

could you tell me how you corrected the BCs?
I am trying to solve a similar problem at the moment.

Kind regards,

Patrick

[wayne14]

Originally Posted by kostnermo

Hi Yan,

could you tell me how you corrected the BCs?
I am trying to solve a similar problem at the moment.

Kind regards,

Patrick

Hi Patrick,

I will email you.

Regards,
Yan