Experimental Comparison of Flow Fields at the Inlet and the Outlet of an Inducer With Shrouded and Unshrouded Configurations

Abstract

The flow field was measured near the inlet and the outlet of an axial flow inducer with shrouded and unshrouded configurations combined with a centrifugal pump. Investigations were conducted using a five-hole probe for several flow rates. The shroud induces a counterrotating flow at the inlet and a blockage effect at the outlet in the region of the tip and for all flow rates. The radial distribution of losses keeps the same shape in both configurations, however, the loss level is higher with the shroud, giving a lower efficiency for the combined inducer-impeller configuration. Effects of shrouded inducer on part load instability are not clear and deserve more research, which is in progress.