On the Study of the Flow through an Impeller of Mixed and Inward-Flow Radial Turbines : 2nd Report, Experiments of Turbines with a Small Number of Blades and with Edge-Cut Hub

抄録

Firstly, it is experimentally shown that the analytical method developed in the 1st report for a flow of nonviscous and compressible fluid through the impeller of a mixed and inward-flow radial turbine is also applicable to a flow through an impeller with small number of blades. Secondly, pressure distributions on the rotating blades of the impeller under off-design conditions are measured and it is shown that a condition of fluid flowing into the impeller without impulse does not always correspond to the condition of the maximum effective efficiency. Thirdly, the change of performances of a radial turbine due to cutting-off the outer part of the hub of an impeller is theoretically and experimentally studied.