A New Cavitating Pump Rotordynamic Test Facility

The present paper illustrates the operational characteristics of the CPRTF (Cavitating Pump Rotordynamic Test Facility), an experimental apparatus specifically designed for the measurement of rotordynamic fluid forces acting on turbopump impellers in fluid dynamic and inertial/thermal cavitation similarity conditions. The realization of the CPRTF is currently in progress under ASI (Agenzia Spaziale Italiana) funding and consists in the upgrade of the CPTF (Cavitating Pump Test Facility), already available at Centrospazio, Consorzio Pisa Ricerche, Pisa, Italy. The experimental apparatus, operating in water, will be capable of carrying out the measurement of the steady and unsteady forces exerted by the flow on the impellers of cavitating/noncavitating turbopumps. More generally, the facility is designed as a flexible, versatile and inexpensive apparatus that can be readily be adapted to carry out detailed experimental investigations on practically any kind of fluid dynamic phenomena relevant to high performance turbopumps. The main operational requirements, development choices and design trade-offs that led to the final configuration of the facility are illustrated and its performance in testing of cavitating/noncavitating turbopumps under fluid dynamic and thermal cavitation similarity are discussed. Experimental results from a number of turbopump configurations and operational conditions are presented to illustrate the present capabilities of the facility.