Design Method for the Volute Profile of a Squirrel Cage Fan With Space Limitation

The uncontinuous volute profile (UVP) is widely used in the squirrel cage fan to meet the space limitation in the air conditioning system. However, it usually causes an obvious performance drop due to the unreasonable impeller–volute interaction. This paper employs two improved design methods, i.e., downsized volute profile (DVP) and partial flow volute profile (PVP), to enhance the aerodynamic performance of the fan installed in a limited space. Experimental results validate the positive effects of these two design methods on the aerodynamic performance. The results obtained by the flow simulation reveal that the pressure field inside the fan with the improved volute profiles is much more uniform than that with the UVP; thus, the improved volute profiles are beneficial for the increase of the fan pressure rise and the reduction of the flow loss. For the investigated fan, it is suggested that the design method of the DVP is more suitable for slight space limitation, while the design method of the PVP is more suitable for significant space limitation.