Parametric geometric model and shape optimization of airfoils of a biomimetic manta ray underwater vehicle

As a new kind of autonomous underwater vehicle, bionic submersible has many merits such as high efficiency and low costs. In order to obtain such advantages, it is a good way to simulate the shapes of marine animals and apply them to the design of artificial underwater vehicle. In this paper, an optimization system of airfoils is proposed by the improved class-shape-transformation (CST) parameterization method and genetic algorithm (GA). The appearance of a manta-ray-inspired underwater vehicle is rebuilt using the optimal sectional airfoils obtained by the proposed optimization system. Computational simulations are carried out to investigate the hydrodynamic performance of the submersible using the commercial computational fluid dynamics (CFD) code Fluent. The results demonstrate that the maximum thickness of the vehicle increases by 9%, which means the loading capacity is increased. Moreover, the underwater vehicle shows better hydrodynamic performance, and the lift-drag ratio of initial design is increased by more than 10% using the presented optimization system of airfoils.