Assessing drag increase on fishing vessels due to biofouling-induced surface roughness using CFD

Biofouling on ship hulls increases drag, fuel consumption and environmental impact. This study uses Computational Fluid Dynamics (CFD) to simulate biofouling roughness effects on the FAO1 fishing vessel, analysing changes in hydrodynamic resistance. Simulations, validated against experimental data, considered varying roughness levels and vessel speeds. The results show that increased roughness raises both total and frictional resistance, especially at higher speeds, emphasising smooth hull maintenance for fuel efficiency. Moreover, CFD results closely matched empirical data, confirming accuracy. The study found frictional drag increased with roughness, while biofouling reduced hydrodynamic pressure, wake and wave elevation, suggesting lower wave-making resistance in some cases. These findings imply maintaining a smooth hull minimises frictional resistance, but balancing this with potential reductions in residual resistance may optimise overall efficiency.