CFD Online Discussion Forums - plotting a performance curve of centrifugal Fan

Dear Friends; I need you help, please

I just want to simulate and plot the performance curve of single inlet centrifugal fan with spiral casing by CFX5 to compare with real test values. I have real test values/curves with volumetric flow rate vs total pressure, x axis also contains dynamic pressure losses.

- meshes are generated by cfx mesh for both volute and full blade domains.

-analsys type: steady state

-fluid: air ideal gas

-frozen rotor interface model choosen for interface between rotor and volute "pitch change: none" selected.

-from the expert parameters "ggi permit no intersection: t" selected

- for the inlet(volute) and outlet(volute) boundary condition, opening /(static pressure entrain)selected.(for the first run; 0 Pa relative pressure selected for both outlet and inlet to see max air flow)

I hope these BCs and aproaches are suitable for this simulation.

my problems are; - what should I do for the define another points on the performance curve.For example; Can the raising relative static pressure entrain to 100pa at the outlet give me the point of (100Pa,x [m^3/s]) on the curve?

- another problem is; I calculate different volume flow rates if I calculate from (massflow rate / density @outlet) or Areaint(velocity)@outlet , flow rates also seen different at outlet and inlet according to velocity.

-finaly which equations should I use to reveal dynamic pressure loss between volute inlet and outlet for the certain run (0Pa static entrain pressure @inlet and outlet).. And for the calculating fluid power?

Thanks for any kind of help. Altano