A Numerical Study on the Effects of Leading-Edge Modifications Upon Propeller Flow Characteristics

This paper reports upon a numerical investigation into the implementation of tubercles in marine propellers. Although they have been mooted as a possible flow control solution in propeller designs, their exact implementation and performances have so far been virtually non-existent. In this work, global performance of a tubercle-modified propeller in terms of thrust and torque are determined from numerical simulations. These quantities are taken across various advance ratio values as well. Results show that implementation of tubercles on the propeller is able to improve thrust by up to 1.5%, specifically at lower advance ratio values. However, decreases in propeller efficiency are also observed. In particular, propeller efficiency only shows improvements above the baseline values when the advance ratio is 0.85 and beyond. Lastly, wall streamlines and surface pressure results are presented to shed light upon the influences exerted by the tubercles upon the propeller blade flow fields.