Research on the influence of endwall on the hydrodynamic performance of shaftless rim-driven thruster

In order to guide the hydrodynamic design of rim driven thruster (RDP), this paper studies the influence of main geometric characteristics of RDP on its hydrodynamic performance with CFD method. Firstly, the effectiveness of CFD numerical method to analyze the hydrodynamic characteristics of RDP is verified. Then, based on CFD, the main factors affecting the hydrodynamic performance of RDP are studied, including the length diameter ratio of the duct, the diffusion ratio, the contraction ratio of the duct, and the tip diameter ratio of the blade. The results show that the optimum aspect ratio of RDP increases with the load factor and tends to a limit value. Compared with the diffusion ratio and contraction ratio of the catheter, the length diameter ratio of the catheter can dominate the design optimization of the RDP; the optimal diffusion ratio of the RDP decreases with the load factor and tends to a limit value. The results show that the optimal diffusion ratio decreases with the aspect ratio, and the effect of RDP contraction ratio on hydrodynamic performance is less significant than that of diffusion ratio and length diameter ratio. The optimal tip diameter ratio of RDP increases linearly with the load factor and decreases with the length diameter ratio; the optimal tip diameter ratio of RDP increases with the load factor, and the hub free RDP has a smaller optimal tip diameter ratio than the hub RDP. The research results can provide a reference for the hydrodynamic design and optimization of the rim thruster.