This paper is to calculate the fully 3D steady flow in a centrifugal rotor by time marching finite volumn method. The use of a nonoverlapping grid makes resulting process simpler,faster, and more accurate. A distributed body force term added in Euler momeotum equtions calculates low energy fiuid by impirical input data so as to simulate viscious effects in real flow with little extra cost of CPU time. Since the flow condition in centrifugal rotor is complex, a jet-wake model usually forms at the impeller exit, it is necessary to adopt 3D computational technique and viscosity should be considered in numerical simulation to reduce the loss of efficience at design.
Four types of axial fans noise energy are measured and compared with prediction byvortex sheddying model(T.fukano). A correct factor is advised in case of large hub rotor ormore blades and big assemble angle.
