@Aitor ! Thank you for your reply! And Yes ! My model is 3D. Do you mean the results of my velocity is correct? Can you detail me more? Thank You!

I do not find anything wrong in your reasoning. Have you checked everything (mass flow rate, density and velocity) at 'Reports' - 'Surface Integrals' and 'Reports' - 'Fluxes'? With these values you should be able to detect the error.