A computational and experimental evaluation of the performance of a centrifugal fan volute

A detailed experimental study of the performance of two radial-flow fan volutes has been carried out at the Science University of Tokyo. This included a volute with a full tongue, such that no recirculating flow occurred, and the same volute but with the tongue cut back to allow flow recirculation. Detailed velocity and pressure distributions at a wide range of azimuth angles were obtained experimentally and are presented. At the University of Bath a computational model, using the k-epsilon turbulence model, has been used to predict the internal flow of both volutes, with particular attention given to the tongue flow. Predicted flow separation at the volute tongue has been demonstrated experimentally through laser sheet studies at the Science University of Tokyo. The performance of the volutes is discussed and the computational fluid dynamics (CFD) analysis is used to recommend design improvements for the volute.