[fedvasu]

Hi,

I have a very basic question, what should be the outlet boundary condition if I have multiple inlets with different fluid velocity and temperature?

I am currently using something like this

Inlet0
    {
        type             fixedValue;
        value            uniform 1000;
    }

    Inlet1
    {
        type              fixedValue;
        value             uniform 300;
    }

    Inlet2
    {
     	type             fixedValue;
	value            uniform 300;
    }

    outlet
    {
     	type          inletOutlet;
	value         300;
	inletValue    300;
    }

my solver is rhopimplefoam. is that OK?

Any corrections welcome.

[T.D.]

Hi,

It depends on what you need to do exactly..

regards,
T.D.

[fedvasu]

Originally Posted by T.D.

Hi,

It depends on what you need to do exactly..

regards,
T.D.

I just want a simple mixing of two streams which have different velocity and temperature.
(interested in mixing pattern)

I don't much care for the outlet as long as it is consistent.

[T.D.]

Hi,

you can use "type zeroGradient" for velocity at outlet,
and for pressure:
outlet { type fixedValue; value uniform 0; }

Good Luck

regards,
T.D.

[fedvasu]

Originally Posted by T.D.

Hi,

you can use "type zeroGradient" for velocity at outlet,
and for pressure:
outlet { type fixedValue; value uniform 0; }

Good Luck

regards,
T.D.

Thanks TD,

But does uniform 0 pressure makes sense?

because the pressure is physical pressure isn't it? I have kept outlet as 1 atm, same as internalfield and velocity is as you have mentioned.

But I am not so sure about temperature.

[fedvasu]

Originally Posted by fedvasu

Thanks TD,

But does uniform 0 pressure makes sense?

because the pressure is physical pressure isn't it? I have kept outlet as 1 atm, same as internalfield and velocity is as you have mentioned.

But I am not so sure about temperature.

Old thread of mine, now I know more.

Whenever in doubt use zeroGradient for velocity and other scalars(temeprature, species mass fractions etc) for outlet.

and fixedValue for pressure for the outlet.(typically ambient pressure).