Abstract
In the low specific speed range, performance improvement of centrifugal pump is one of the important issues. The present study is focused on performance improvement in the range of low specific speed, and a new type centrifugal impeller with J-Groove mounted at the back of both front and rear shroud is proposed and tested. The results show that the proposed device is effective in the range of ns<150(m, m3 / min, min-1). J-Groove raises up pumping head by 25%, which is caused by rapid increase of fluid velocity in a volute. In addition, the unstable head-capacity curve becomes stable. It is also clarified that the reduction of impeller diameter is possible without changing the pump overall performances.
