Study on an Impeller with Radial and Circumferential-Flow Channels

Abstract

Various types of centrifugal impellers have been proposed to achieve low flow rates and high heads. To improve the performance and suppress an upward-sloping unstable characteristic in the head curve, this paper suggested a new impeller in which radial and circumferential flow passages are regularly and geometrically arranged, and a one-dimensional performance prediction method is also proposed. As a result, the impeller suppressed an upward-sloping unstable characteristic in the head curve, and the best efficiency was found to be about 40% for a flow rate of 0.061 m3/min. Furthermore, the results clearly indicate that a one-dimensional performance-prediction method can easily calculate the total loss of the impeller from the best-efficiency-point flow rate to the excess-flow rate.