PIV Flow Analysis in a Multi-Blade Fan Using a Impeller with Divided Blades by a Slit

Multi-blade centrifugal fan is one of the most important devices in air conditioning system for automobiles. In design of the fan, downsizing, noise reduction and power saving are fundamental factors. Especially, the improvement of fan-efficiency is highly demanded from environmental viewpoint. In order to meet these requirements, an impeller with divided blades by a slit for the multi-blade fan is proposed in this report, and its basic characteristic has been investigated and discussed by comparison with other two types of blades. And also the effect of blade division by slit on the flow through the impeller has been analyzed by velocity vector maps obtained by PIV.