[zona]

I'm having a problem calculating a pump (spiral pump inlet-impeller-pump spiral (outlet))

I'm using only frosen rotor (someone thold me that this is OK for calculating pump Q-H curve and efficiency)
the problem is that I allvays get efficincy to be 3-6 %% less that is should be (in optimal point)
an the q-h curve is not as expected in lower q than otimal it has lower H and for greater Q i get higher H than the expected curve

this is what i do
after starting CFX pre import meshes (gtm) (inlet-impeller-pump) for inlet I have mass flow (for example 300 kg/s) and for outlet preasure (0 Pa), what is the reference preasure ? (also 0 Pa or atmosphere preasure)

and after the solver in CXF post, when I go to MAcro Calculator - > Liquid Pump Performance , what Reference Radius and Reference High mean (diameter of impeller / 2 and hight difference between inlet and outlet)

Please someone help, I was traying to find tutorial for similar problem but only found one tutorial for axial turbine and that is very different

I'm willing to give the files to someone who wants to help me solve this kind of problem