Characteristics of Aerodynamics and Noise for Centrifugal Fan without Scroll Casing : Effect of Inlet and Outlet angles
抄録
The influence of the inlet and outlet angles of the centrifugal fan without scroll casing were investigated in relating to the characteristics of aerodynamics and noise. The following results are obtained. The inlet angle of the impeller, which is estimated by the radial inflow condition, gives the extremely low angle for the inflow condition. The cause is that the leakage flow from the clearance between the front shroud and the bell mouth is very large and has the tangential component of velocity. And we proposed the new charts of the performance on the fan noise. They clearly indicate the effect of the inlet and outlet angles of the impeller to the performance of the fan noise. From the charts, the optimal design parameters and the sensitivity of them to the fan noise can be easily obtained.