hi, all;

My project is about airconditioning outdoor unit modeling which include a propeller fan . I want to use mixing plane model. Since our target is to calculate CFM , which boundary condition should I use for downstream, Mass flow inlet or pressure inlet?

If I use mass flow inlet , then How to specify the average mass flux for mass flow inlet?

thanks for attention

Hi,

If youre going to model the whole AC unit, model the fan as lumped, by specifying its P-V curve if you know it. If you just have the geometry but no curve, then model it with MRF not MPM. Use pressure inlet and pressure outlet BCs.

Regards, Emre

Hi,Emre:

Thanks for your kindly help!

In fact, I only have used the MRF with pressure inlet/outlet boundary condition. The reason I want to use Mixing plane is to see whether the results can be improved. Could you elaborate on why I can't choose MPM if fan curve is unknown.

Regards,

Ellen

Hi Ellen,

In order to improve your results you could use sliding mesh model, which is computationally more expensive since you have to solve unsteady flow. I have seen applications of MPM only for rotor-stator interactions.

Best Regards,

Emre