Effect of the incline angle of propeller boss cap fins (PBCF) on ship propeller performance

In order to understand the effect of modifying the traditional form of propeller hub into the propeller boss cap fins (PBCF) form, a series of tests was conducted to discover the best type. Analysis was made using the computational fluid dynamic (CFD) approach, together with ANSYS CFX code. Two types of hub were employed, namely convergent and divergent. Both types were made using slope angles of 5, 10 and 15 degrees. Comparative analysis of the data was made, combined with validation by published papers. The overall results indicate that compared to a normal hub, the traditional convergent type has an increased efficiency of around 1.4%, while the divergent type decreases efficiency by approximately 1.2%. Furthermore, the PBCF convergent hub results in increased efficiency of around 0.8%, whereas the divergent type decreases efficiency by about 1.0%. This study is in good agreement with previous papers, with a discrepancy of approximately 2%.