Hull form optimization in waves based on CFD technique

摘要

The seakeeping behavior of a ship in waves is different from its behavior in calm water. The resistance and seakeeping performance of a ship are of great importance and must be considered in the early-stage design of a ship’s hull form design. Therefore, this paper proposes a hull form optimization framework aiming to achieve the minimum total resistance in waves using a CFD technique. A sinusoidal wave is adopted to establish the numerical wave tank and the overset mesh technique is used to facilitate the motions of the ships in question. Considering the motions of pitching and heaving, the total resistance of the hull in waves is regarded as the objective function which is calculated using the Reynolds averaged Navier–Stokes (RANS) method. The arbitrary shape deformation (ASD) technique is used to change the geometry. Under displacement and design variables, a hybrid algorithm is developed to evaluate the objective function combining the optimal Latin hypercube design (Opt LHD) and the non-linear programming by quadratic Lagrangian (NLPQL) algorithm. Finally, two examples of hull form optimization are presented and discussed for David Taylor Model Basin (DTMB) model 5512 and WIGLEY III cases. The results show the effectiveness of the optimization framework developed in the present study, which can lay the foundation for further optimization of full-scale ships.