[Andrea23]

Hi,

I am simulating a room with swirl diffuser like in the image; and I have some doubt on how to implement the BC.




I would appreciate your help, if you could help me these are my doubts:

I think the best way to simulate the diffuser downstream airflow is to use "swirlFlowRateInletVelocity" BC, or is there a better way?

In case this BC is correct,

<patchName>
{
type swirlFlowRateInletVelocity;
flowRate constant 0.2;
rpm constant 100;
}

assuming that i know the flowrate, and so the normal velocity component, and the tangential velocity component (calculated from measured magnitude velocity) what rpm value should I use? I have not found the formula to calculate rpm

My boundary surface includes all 24 slites, so it is 1 entity, I assume the swirl obtained is one "big" swirl, like in the image, and not 24 little swirles one for each slite, is it correct?

[Andrea23]

I found the answer, RPM is the fluidflow rpm not the rpm of a hypothetical fan, so the tangential velocity is equal to RPM*PI/30 (conversion RPM to rad/s) * radius (distance from boundary surface center). And in this case it creates one big swirl per diffuser