Characteristics of Aerodynamic and Noise for a Centrifugal Fan with Inducer

An investigation of characteristics of aerodynamic and noise for a centrifugal fan with inducer and without inducer was coducted. The noise generated by these two kinds fan consists of the discrete frequency noise and the turbulent noise. The discrete frequency noise can be disintergrated into the rotating noise and noise due to the vibration of motor. The noise level of the later is heiger than that of the former. This discrete frequency noise level can be reduced by make firm the motor support. The overall noise radiated from the fan with inducer is lower than that of which without inducer over wide flow rate. In the pressure and the efficiency, the former is heiger than the latter. The specific noise level of the former is lower than that of the latter. Therefore, the centrifugal fan with inducer is superior to that without inducer. The agreement between the predicted values and measured values of the sound pressure level was generally satisfactory