The Evaluation of Propeller Boss Cap Fins Effects for Different Pitches and Positions in Open Water Conditions

Abstract

The operation of marine vessels with high efficiency provides a great contribution within the scope of the International Maritime Organization and the sustainable development goals. In terms of the propulsion system, selecting the appropriate propeller is critical to effectively use the engine power installed in marine vessels because the biggest energy losses during transmission occur on the propeller and ship hull. Increasing propeller efficiencies above a certain level is quite a challenge by simply changing the number of blades, pitch, or propeller type. Therefore, various energy-saving device applications, such as propeller boss cap fins (PBCFs), are performed on the ship propeller. The effects of National Advisory Committee for Aeronautics 4415 profile PBCFs which have a different position and pitch angle integrated into the E698 model propeller have been investigated to describe efficiency, vortex, and pressure distributions based on the KRISO very large crude carrier 2 designed hull in this study. The E698 model propeller has been created by the 3D software and the validation has been performed by the computational fluid dynamic solver software based on the reference values of the propeller. The effect of four PBCF applications which have different pitches and positions on the model propeller has been revealed in terms of the efficiency, pressure distributions, and vortexes. Although P45-R45 and P45-R90 PBCF applications are quite close to the E698 propeller in terms of efficiency, no significant efficiency increase has been observed. In addition, the efficiency has decreased considerably in P90-R45 and P90-R90 applications. PBCFs application with P45-R90 has provided superiority to the base model in terms of pressure distributions and vortex formation. However, any improvement has not been achieved in the remaining three designs. Therefore, PBCF applications should be applied quite elaborately based on propeller types.