HYDRAULIC PERFORMANCE MODEL FOR THE OPEN REV EVO PUMP

This technical note presents the empirical model describing the hydraulic performance of the high-speed pump design internally named as OpenREV EVO. The latter 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 update and extend to the entire pump operation range the equations suggested in a previous note as base for a mathematical model of the pump hydraulic performance in operation around its best efficiency point. To this purpose, additional experimental data acquired by T4i for pump operation up to the maximum flow rate were included in the data set used to define an appropriate polynomial curves fitting model of the dimensionless pump performance parameters. The revised model incorporates corrections accounting for the effects of the Reynolds number in order to obtain as output reliable values of the pump pressure rise and hydraulic efficiency as a function of the pump mass flow rate, impeller rotational speed, and molecular properties of the working fluid. The model was used to build the dimensional maps of the 45mm diameter OpenREV EVO prototype in operation with the fuel and the oxidiser. To further exploit the capabilities of the model, the performance maps expected by the OpenRev EVO prototype if manufactured with a 40mm diameter impeller are presented as well.