Numerical Evaluation of Roughness Influences on Open Water Propeller Characteristics Using RANSE Method

This paper presents the influences of roughness on ship propeller’s performance by using RANSE method with moving reference frame approach. The effect of different roughness conditions on the propeller efficiency was evaluated for several different advance coefficients. The numerical obtained results indicate that the thrust of propeller coefficient decreases while the torque of propeller coefficient increases with increasing roughness levels on propeller surface, which leads to a reduction of the propeller open water efficiency. Besides, the paper also investigates into the roughness effect on the pressure, wall skin friction coefficients, and velocity field in order to explain the physical phenomenon of changing propeller characteristics at different roughness levels. The study indicates the proposed RANSE method is capable to apply as a reliable approach to predict the effects of fouling on ship propeller efficiency. The well-known benchmarking Potsdam Propeller was used as test case in this study.