PRELIMINARY HYDRAULIC PERFORMANCE MODEL FOR THE OPEN REV EVO PUMP

This brief technical note deals with a preliminary empirical model aimed at describing the hydraulic performance of a partial emission pump operating in the around of its own best efficiency point. In particular, the high-speed pump design internally named as OpenREV EVO is considered. Such design is the more recent evolution of the partial emission pump prototypes conceived to pressurise the fuel and oxidiser of a rocket engine to be installed in a European lunar lander, being developing by NAMMO UK under ESA funding. The aim of the technical note is to report the equations suggested as base for a mathematical model of the pump hydraulic performance. To this purpose, the experimental data acquired by T4i were made dimensionless and approximated by polynomial curve fitting. The polynomials describing the dimensionless performance were finally rearranged to obtain dimensional equations of the pump pressure rise and hydraulic efficiency as a function of the pump mass flow rate, impeller rotational speed, and mass density of the working fluid. The results show the dimensional maps of the 45mm diameter OpenREV EVO prototype in the operation with the fuel and the oxidiser, as obtained using the presented equations, superimposed to the 50%, 100% and 117% nominal operation point requirements.