[u k jha]

hi, all,
i am simulating an centrifugal fan by using cfx 11.0.
in the simulations i gave the boundary condition as the total pressure inlet and the mass flow rate at the outlet.the results are coming. but not satisfying as as mass flow rate increases at the same rpm. the static pressure difference between inlet and outlet is decreasing that's true but afterward it goes in negative means the outlet pressure is lower than the inlet pressure. why it is happening? any one can suggest me. my simulation is in steady state.

u k jha

[ghorrocks]

Hi,

Are you sure the impeller is spinning in the right direction?

You should compare total pressures between inlet and outlet. Otherwise Bernoulli and his equation can stuff up the comparison.

Glenn Horrocks