Study on a tracked amphibious robot bionic fairing for drag reduction

In this paper, to reduce navigational resistance and energy consumption and to promote the efficiency of a novel track-propeller composite amphibious robot, a bionic fairing inspired by hammerhead sharks is proposed. Three types of fairing devices for underwater navigational resistance reduction are designed based on the bionic principle of hammerhead sharks. On this basis, the structural drag characteristics of four models, including an original model and three amphibious robot models with bionic fairings, are evaluated through computation fluid dynamics (CFD) analysis based on lattice Boltzmann method (LBM) theory. Experimental studies on the bionic fairing drag reduction of the amphibious robot model are conducted. In the experiments, the drag reduction effect of the bionic fairing devices is investigated considering two models and three speeds (0.5 m/s, 1.0 m/s, 2.0 m/s). Compared with the original model of the amphibious robot, the simulation and experimental results demonstrate that the bionic fairing devices inspired by the hammerhead shark head have a significant resistance reduction effect, the drag coefficient can be reduced by 23%, and the experimental results reveal a maximum drag reduction rate of 22%. This study provides an essential reference for the design of tracked amphibious robots with underwater navigation functions, reveals the drag reduction mechanism of the hammerhead shark head, and expands the bionic object of existing resistance reduction studies.