Design and Analysis of Underwater Drag Reduction Property of Biomimetic Surface with Micro-nano Composite Structure

Underwater drag reduction has an important impact on the speed and energy consumption of underwater vehicles. This is directly related to whether it can improve the operating efficiency of the underwater vehicle and whether it plays a role in energy-conservation and emission-reduction. A new type of bionic surface with micro-nano composite structure, which is designed to achieve drag reduction of the underwater vehicle is presented. And it is applied to a fish dart. The design source of the structure comes from dolphins’ ridge skin and mosquitoes’ mouthparts. The design of the structure is based on the method of bionics. A fluid mechanics method is taken to simulate the drag reduction effect of the micro-nano composite structure. According to the results of simulation optimization, the drag reduction mechanism of the composite structure is analyzed. From the analysis, the optimal structural parameters can be obtained. The simulation results show that the underwater drag reduction rate can reach 89.49% in the optimal structural parameters.