Effect of geometric parameters of contra-rotating propeller boss cap fins on the marine propeller

This study investigates the influence of geometric parameters (diameter, pitch, and chord length) of contra-rotating propeller boss cap fins (CRPBCFs) on propeller performance using large eddy simulation turbulence modeling and overset mesh techniques in STAR-CCM+. The numerical simulations demonstrate good agreement with experimental data in predicting open-water characteristics, as validated through comparative analysis. Research has shown that as the diameter of the boss cap fins increases, thrust and torque also increase, but an excessively large diameter can result in a reduction in efficiency. When the pitch of CRPBCFs is small, both the thrust coefficient and torque coefficient decrease relative to the benchmark propeller. At chord length ratios of 0.2 and 0.3, the overall efficiency change is relatively small. This study has a certain reference value for the preliminary design of the CRPBCFs.