[dela]

Hello community,

I am working on a small project and wants to use a patch for both inlet of gas and outlet of liquid. I am using OFv 1806. Please is there a way I can do this with groovyBc or any other way?
Thank you

[gkarlsen]

Originally Posted by dela

Hello community,

I am working on a small project and wants to use a patch for both inlet of gas and outlet of liquid. I am using OFv 1806. Please is there a way I can do this with groovyBc or any other way?
Thank you

I don't think you need any special BC to do that. How about something along these lines:

//For alpha

    myPatch
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }

//For U

    myPatch
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }

For p_rgh

    outlet
    {
        type          prghTotalPressure;
	p0		uniform 0;
        value        uniform 0;
    }

This will allow water to exit through myPatch. In case there is inflow, the inflow will be air

[dela]

Thank you very much @gkarlsen

That looks OK but how will that work for an eulerian simulation where different alphas are defined for both gas and liquid?

For instance, I want 'myPatch' to be a gas inlet and a liquid outlet
So for alpha.gas, can i write

mypatch
{
Type fixedvalue;
value uniform 1;
}

And alpha.liquid,

mypatch
{
Type fixedvalue;
value uniform 0;
}

Can this out? Will liquid be aloud out of this patch?

Thank you

[gkarlsen]

Originally Posted by dela

Thank you very much @gkarlsen

That looks OK but how will that work for an eulerian simulation where different alphas are defined for both gas and liquid?

For instance, I want 'myPatch' to be a gas inlet and a liquid outlet
So for alpha.gas, can i write

mypatch
{
Type fixedvalue;
value uniform 1;
}

And alpha.liquid,

mypatch
{
Type fixedvalue;
value uniform 0;
}

Can this out? Will liquid be aloud out of this patch?

Thank you

No,

Use InletOutlet as stated above, not fixedvalue. You set the parameter inletValue to whatever value you would like when there is flow in to your domain from the patch. Alpha for discharge from the domain will be according to whatever local conditions are present at the boundary (liquid if there is liquid on the inside, gas if there is gas on the inside and so on).

[dela]

Alright, that's clear, thank you very much.
But one more question, how do I specify the velocity of the gas at the patch using pressureInletOutletVelocity?

Thank you

[gkarlsen]

Originally Posted by dela

Alright, that's clear, thank you very much.
But one more question, how do I specify the velocity of the gas at the patch using pressureInletOutletVelocity?

Thank you

You don't . This BC automatically calculates velocity based on pressure. If you need to set a given velocity you have to use something else