Similarities and Geometrical Effects on Rotating Cavitation In Two Scalted Centrifugal Pumps

Abstract

Two scaled centrifugal pumps with vaneless radial diffuser running at identical Reynolds-Numbers are in the focus\nof experiments at Technical University of Braunschweig and Darmstadt University of Technology in the frame of a\ncooperation hosted by the DFG (Deutsche Forschungsgemeinschaft). Both pumps can hold different runner\ngeometries as well as different leading edge geometries within the same runner. This paper describes experimental\ninvestigations of different configurations in both pumps. All configurations show the occurrence of a periodic\ncavitation state called "rotating cavitation" in a wide range of part load conditions, which onset can be characterized\nby an almost constant value of the dimensionless parameter ó/2á. Comparison of the main characteristics of both\npumps as well as optical investigations to determine the dynamic properties in cavitating conditions have been carried\nout.