Numerical Simulation of the Influence of Inclined Volute Tongue on Flow Field and Noise of Multi-blade Centrifugal Fans

The flow field and noise of the straight volute tongue and the inclined volute tongue in multi-blade centrifugal fans were simulated respectively using the software Fluent.The simulation result shows that the influence of the inclined volute tongue on the velocity field of the multi-blade fan was mainly concentrated in the volute tongue region.The inclined volute tongue can reduce the velocity in the volute tongue region,alter the fluid velocity vector on the volute tongue surface,and decrease the local cyclone in the volute tongue region.In the case of the same speed,although the flow rate of the multi-blade centrifugal fan with inclined volute tongue was reduced by 5.76 % in comparison with that with straight volute tongue,the power of the impeller was reduced by 9.13 %,and the noise was also reduced by 12.2 dB.So,it is significant for reducing energy consumption and noise.