[FireN]

Hello
I have task to simulate and compare three different geometries of duct supplying air to fan(from one bottleneck to merely free from obstacles) and i have question about determining boundary conditions in this case. I would like the flow to be induced by fan rotation (steady state with reference frame).
In this case air is taken from ambient air and is released to ambient air. How should I set up BCs at the inlet and outlet? Should they be pressure inlet and pressure outlet with gauge pressure 0?
I would like to know hom much air can the fan move when at constant RPM in three cases.

thanks in advance for your replies

[LuckyTran]

Yes. Use a stagnation / total pressure inlet and pressure outlet. Set the inlet total pressure to ambient (0 gauge pressure) and outlet static pressure to ambient (0 gauge pressure). Simulate it and then get then the flowrate from post-processing.