An advanced prediction method of ship resistance with heterogeneous hull roughness

Despite the ongoing efforts for predicting the effect of hull roughness on ship resistance, the majority of the studies have been treating the hull surfaces as uniformly (i.e., homogeneously) rough. This can be a limiting factor since the real ships' hulls are not uniform due to various reasons such as the heterogeneous accumulation of biofouling. The current study aims to propose a new prediction method for added resistance due to heterogeneous hull roughness. This newly proposed method incorporates the similarity law scaling and the Roughness Impact Factor to consider the relative impacts of hull roughness in different regions. Two separate case studies involving recent Experimental Fluid Dynamics (EFD) and Computational Fluid Dynamics (CFD) results were used to assess the newly proposed method, which showed better prediction performance compared to the conventional method.