A Method for Optimizing the Hull Form of Fishing Vessels

Hull optimization is an important aspect of ship design to improve safety and economic-technical efficiency for ships. This problem has been studied for a long time and has achieved many significant results, but in practical applications, there are still some contents that need to be improved such as the presentation and transformation of the existing hulls, an optimal mathematical model suitable for a specific type of ship, or method for solving the objective function, etc. On that basis, in this paper, a method for optimizing the hull form of fishing vessels is presented, including algorithms using interpolating cubic spline to generate the existing hulls that pass exactly through the given offsets and are constructed in a format to use both Computational Fluid Dynamics (CFD) analysis in resistance prediction and Lackenby method in hull form transformation, a suitable mathematical model for hull optimization problem of fishing vessels, an effective solver based on a combination of CFD, Kriging surrogate models, and traditional optimization techniques. In addition, solutions for improving the accuracy of CFD-based resistance predictions are also presented based on ensuring the accuracy of the 3D hull models and determining the suitable input parameters used for CFD simulations. This study was applied to optimize the hull form of a Vietnamese traditional wooden fishing vessel, symbol MH076, and obtained results that are consistent with the theoretical and practical trends, with the deviations of CFD-based resistance values and corresponding model test data are within the range of 63% and the reduction in total resistance or required power at design operating is around 8.81%.