A Study on the Effects of Propeller Pitch Variation for Propeller-Rudder Interaction

Paper in proceeding, 2026

The ongoing development of wind-assisted ship propulsion is leading to a paradigm shift in propeller design and operation. The propeller needs to be efficient over a wide range of conditions associated with its unloading, which may also have an impact on rudder performance. Controllable pitch propellers offer the possibility of achieving adequate efficiency for multiple conditions, with proper pitching of the blades. In this paper, we present experimental and numerical results carried out for a propeller-rudder configuration, tested for a wide range of rudder angles, propeller loading conditions, and three pitch settings for the propeller blades. Studies on the propeller and rudder performance when isolated from each other were performed as well. The results show that the presence of the rudder leads to increased thrust and torque generation on the propeller, whereas the unloading of the propeller can cause a significant decrease in the rudder forces. For equivalent conditions, changing the pitch of the propeller can lead to higher efficiency when the propeller is strongly unloaded without impacting negatively the rudder forces.