Effect of Number of Blades on Performance of an Axial Flow Hydraulic Turbine with a Collection Device

Abstract

A hydraulic turbine for open channels does not need incidental facilities for conducting water. It is applicable even if an effective head is comparatively low. However, because the rotational speed is low, the hydraulic turbine has a tendency to enlarge. Therefore, the hydraulic turbine is fixed to a setting position. A new portable hydraulic turbine that utilizes the kinetic energy of an open-channel flow, such as a river or an irrigation canal, has been proposed. This hydraulic turbine has added a collection device to the axial flow runner with the aim of increasing output by collecting and accelerating the flow. In this study, characteristics and flow fields of the runner simple substance, and the complex of the runner and collection device which differ in number of blades are clarified by numerical analysis. Furthermore, the effect of the number of blades on the performance of this hydraulic turbine is clarified.