CFD Online Discussion Forums - Pressure BCs in buoyantPimpleFoam

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Pressure BCs in buoyantPimpleFoam

Hello FOAMers,

I am using buoyantPimpleFoam to simulate a air flow within a furnished room.
Attachment 32119
I have one inlet, one outlet, and some furniture some of which act as heat sources (computers,lights,occupants).

But I am confused when setting pressure boundary conditions at inlet,outlet and walls.

p_rgh:

Quote:

internalField uniform 1e5;

for the walls/furniture:
type zeroGradient;

for inlet:
type zeroGradient;

for outlet:
type fixedValue;
value 1e5;

Quote:

internalField uniform 1e5;

everything else:
type calculated;
value $internalField;

Quote:

inlet:
type fixedValue
value uniform (0 0 0);

outlet:
type zeroGradient;

everything else (0 0 0);

Do these make sense? If not can anyone explain to me how I should set these up?

Thanks in advance,

Ian

Have a look at the tutorial of buoyantPimpleFoam:
https://github.com/OpenFOAM/OpenFOAM...Foam/hotRoom/0

For the pressures (p_rgh) on the walls you probably want something like fixedFluxPressure.

0 velocity for the inlet does not make sense, because then its a wall.

Thanks for the reply!

You are right! My inlet should have a value.
It is actually:

type fixedValue
value uniform (0.086 0 0)

Maybe you know more about fixedFluxPressure. From what I understand is that it will calculate pressure based on the mass flow rate normal to the surface. Is this correct?

Also, can this be used as a BC for p_rgh at my inlet as well?