Tip vortex control effect and open-water performance of grooves in a pumpjet propulsor

Abstract

To control the flow field of tip clearance in a pumpjet propulsor and suppress tip vortex cavitation, a certain number of grooves were set in the inner wall of the duct of a pumpjet propulsor. Based on the detached eddy simulation method and high-quality structured grid, a numerical calculation of the tip clearance flow field of the pumpjet propulsor was performed, and an open-water performance test of the pumpjet propulsor based on a towing tank was designed and performed. The effects of groove structure on the shape of the tip vortex, tip vortex core pressure, and open-water performance were compared and analyzed. The results show that the groove structure can substantially increase the core pressure of the tip vortex, the mean value of the relative pressure of the vortex core can be increased by at least 36.57%, and the volume of the low-pressure region of the tip vortex behind the rotor trailing edge can be reduced by 65.8%, which can effectively delay the tip vortex cavitation. In addition, the groove structure has little impact on the hydrodynamic performance of the pumpjet propulsor and can improve the propulsion efficiency to a certain extent.