RANS study of surface roughness effects on ship resistance

Abstract In marine engineering, optimizing the performance of vessels is a key issue, particularly in increasing fuel efficiency, reducing operating costs, and minimizing environmental impact. One of the most critical determinants of vessel efficiency is hull resistance, which directly affects fuel consumption, power requirements, and cruising speed. We aim to investigate how surface roughness affects hull flow resistance, to quantify the drag variation at different surface roughness levels using special wall functions that reproduce boundary layer dynamics. This approach involves the complex interaction between the intricate complexity of roughness and the nonlinear pressure drag effects on the hull. The KVLCC2 ship model is used as a representative prototype in the CFD analysis based on the RANS equations and the k-omega SST model to independently evaluate the roughness effects on individual ship sections. The comparative analysis with empirical data reveals the complex relationship between surface roughness and ship resistance and provides insights for ship design and operational improvement. The study investigates the interaction between drag coefficient and vessel performance to improve hydrodynamic efficiency.