Air Test Flow Analysis of the Hydrogen Pump of Vulcain Rocket Engine

Within the framework of the technological development of the VULCAIN rocket engine (Ariane V European project), initiated by the Centre National d’Etudes Spatiales (CNES) for the Agence Spatiale Europeenne (ESA), the Societe Europeenne de Propulsion (SEP) is in charge of the design and building of the liquid hydrogen turbopump. In order to characterize the hydraulic performance of the pump, an air test facility reproducing the pump geometry was built by SEP and fitted in the Laboratoire de Mecanique des Fluides et d’Acoustique of the Ecole Centrale de Lyon. Benefits and disadvantages of air tests of hydraulic pumps are discussed. The pump is composed of three stages. The first one is an axial inducer stage. The second and third ones are centrifugal stages with vaned diffusers and are separated by a U bend and a vaned return channel. Results of the first measurement campaign are presented. They consist of overall pressure, wall static pressure and velocity measurements. Local quantities (velocity triangle, pressure) and mean quantities (pressure rise, losses, efficiency) are given. Recirculating and wake flow analysis are included. The goals of the study are the understanding of the flow behavior and the improvement of the prediction methods. Predicted and measured quantities (losses, efficiency, kinetic momentum) are compared. The hydrogen performances are deduced, they agree with the specified performances of the pump. This validation is one of the main results achieved.