An Experimental Investigation of Flow in Blade Passage of Radial Inflow Turbine

Abstract

In this paper, the flow patterns in the blade passage of a radial inflow turbine are presented in three dimensions. The technique of tracer particles is developed in order to make three-dimensional analysis of a photograph of particles taken by means of the conventional double-flash illumination. The development is attained by the methods in which the diameters of the circles of diffusion of the picture of particles taken out of focus are measured, because the perspective distance can be estimated from them. The availability of this three-dimensional method is verified by the experiments; therefore, in three dimensions, the particle trajectories can be compared with the flow patterns predicted by the compressible inviscid theory. The results show in a radial portion that the trajectories are in fairly good agreement with the flow patterns under the condition of shock free entry, and that the secondary flow and the flow passing through the axial clearance are appreciably feeble. Further, the theory is inapplicable to the run of reduced speed of rotation.