Experimental study on the noise reduction of an industrial forward-curved blades centrifugal fan

Many previous researches have concentrated on the noise of backward-curved (BC) blades and forward-curved (FC) multi-blade centrifugal fans. In this paper, an experimental study has been carried out to study the noise reduction of an industrial FC blades centrifugal fan. First of all, the performance and noise characteristics of the FC centrifugal fan were tested to compare the similarities and differences from those of BC blades and FC multi-blade centrifugal fans. And then, some different volute geometric configurations were carried out in order to study the effects of inclined volute tongue, impeller blade-tongue clearance, hub-volute clearance and their coupling effect to the performance and noise of the FC blades centrifugal fan. The aim of many different experimental tests is to validate whether the effects of different modifications to fan performance and noise are additive and to find a good impeller-volute matching to reduce the centrifugal fan noise without reducing performance. The experimental results show that a good coupled modification not only could reduce the fan noise but also could advance the fan performance and extend the operating range.