Automated CFD-based optimization of inverted bow shape of a trimaran ship: An applicable and efficient optimization platform

This paper investigates the improvement of the bow region of the trimaran ship hull, and proposes a Computational Fluid Dynamics (CFD)-based automated method to reduce total resistance. The main objectives pursued in the present study include: 1) to create and develop a useful optimization platform to modify the ship hull and 2) to investigate the effect of different inverted bow on the hydrodynamic performance of trimaran ship. A wave-piercing bow trimaran hull was taken as the baseline design. The ship bow has been redesigned using Arbitrary Shape Deformation (ASD) technique, which denes the input variables for the optimization process. The objective function was the drag force, and this study is conducted at cruise speed. To accomplish this task, two optimization methods were sequentially applied. A Latin Hypercube Sampling tool distributes design points and an Radial Basis Function (RBF)-based surrogate model is constructed to investigate system behavior. The nal optimum design of Design Of Experiment (DOE) study was introduced to the direct optimization SHERPA algorithm as a baseline design. The integration of CFD solver, geometric parameterization and optimizer tools is managed by the HEEDS MDO software package using a multi-connection method. The optimization results show that the optimization was successfully carried out and the resistance was reduced by 10.2%. The comparison between the initial hull and the optimized hull shows that the proposed optimization platform can be used for ship hull optimization in industrial application and signicantly reduces the computational time and workload.