[mongya]

Hi, everyone.
I am new to openfoam and I am not sure the BCs that I set are right or not.
Should BCs in p_rgh file be the same as BCs in p file? Or Is it okay to consider them independently?

[Yann]

Hello Kim,

For solvers using p_rgh, your BCs have to be defined in p_rgh.
p BCs would be usually set to calculated.

In such situation, have a look to the tutorials corresponding to the solver you want to use to see how the BCs are defined.

Yann

[mongya]

Originally Posted by Yann

Hello Kim,

For solvers using p_rgh, your BCs have to be defined in p_rgh.
p BCs would be usually set to calculated.

In such situation, have a look to the tutorials corresponding to the solver you want to use to see how the BCs are defined.

Yann

Dear Yann
Thank you for your reply. I set BCs as you advised. But, I am not sure if my BCs are valid. It seems there is not any problem during iterations. Does it mean they are valid?

My BCs in p and p_rgh file are as follows :
BCs in p file

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

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

internalField   uniform 0;

boundaryField
{
/*  the tutorials :  floor
    {
        type            calculated;
        value           $internalField;
    }

    ceiling
    {
        type            calculated;
        value           $internalField;
    }

    fixedWalls
    {
        type            calculated;
        value           $internalField;
    }
*/	
	
	inlet1
    {
		type            zeroGradient;
    }
    inlet2
    {
        type            zeroGradient;
    }
    outlet
    {
        type            fixedValue;
        value           uniform 0;
    }
    airconditioner
    {
        type            zeroGradient;
    }
    wall1
    {
        type            zeroGradient;
    }	
}


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

BCs in p_rgh file

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

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

internalField   uniform 0;

boundaryField
{
/*  the tutorials :   floor
    {
        type            fixedFluxPressure;
        rho             rhok;
        value           uniform 0;
    }

    ceiling
    {
        type            fixedFluxPressure;
        rho             rhok;
        value           uniform 0;
    }

    fixedWalls
    {
        type            fixedFluxPressure;
        rho             rhok;
        value           uniform 0;
    }
*/	

	inlet1
    {
		type            zeroGradient;
		rho             rhok;
    }
    inlet2
    {
        type            zeroGradient;
		rho             rhok;
    }
    outlet
    {
        type            fixedValue;
		rho             rhok;
        value           uniform 0;
    }
    airconditioner
    {
        type            zeroGradient;
		rho             rhok;
    }
    wall1
    {
        type            zeroGradient;
		rho             rhok;
    }	
}


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

Respectfully.

[Yann]

Hello Kim,

The fact your case is able to run does not necessarily mean your setup is physically correct (OpenFOAM will crash or throw an error only if something in your setup is preventing it to solve the equations)

I see you copied and commented some BCs coming from tutorials, but you didn't use these BCs on the actual patches you have in your case.
In p_rgh, your patches defined as zeroGradient should use fixedFluxPressure instead (as it is done in the tutorials) and in p your BCs should be defined as calculated.

Regards,
Yann