Modeling of stall cavitation sensitivity of a booster turbopump assembly and comparison between experimental and numerical results

Nowadays, screw booster pumps (BP) are used in engines of large and small thrust both of Russian and foreign designs to reduce the pressure in the tanks. Cavitation may occur in BPs like in any hydraulic systems. To determine the cavitation characteristics of screw and centrifugal pumps a number of empirical formulas were obtained which do not fully take into account all the geometrical features of variable-step screws. Various models of cavitation are used in CFD programs; cavitation properties of any geometry can be obtained on the basis of these models. The paper presents the results of numerical analysis of the cavitating flow in a booster pump and their comparison with the experimental ones. Modeling was performed by ANSYS CFX. The cavitation phenomena were simulated in a stationary approach using the Rayleigh-Plesset model. The geometrical model included an axial-radial wheel and straightening vanes. The analysis was performed with and without a shroud ring, a clearance gap and roughness. On this basis, a method of calculating the stall cavitation characteristics is developed using ANSYS CFX.