A Study on Flow in Centrifugal Impellers with Passages of Circular-Arc in Meridional Plane

Abstract

The flow in the impeller is affected by the incidence angle. The impellers used in this experiments are of three types ; two of which have constant passage height, but one is with an inducer and another is without, and the other has a constant sectional area all on the way from inlet to outlet, but without any inducer. The influence of incidence angle to the flow in impeller has been measured by the kiel probe and the yaw meter that rotate with the impeller. From this results, it has been recognized that the separation of the flow occurs at the triangle-area that is surrounded by the trailing face of blade and the shroud. The pressure distribution at blade face that has been measured in the experiments is compared with the results of the two-dimensional theory. This theory is found to be in comparatively good agreement with the experimental results, that is, the pressure at the blade face is influenced by the main flow only, and it hardly affected by the secondary flows that complicate the flow through the impeller.