Study On Hydrodunamic Performance Of Fishlike Robot With Tandem Flapping Wings

Autonomous underwater vehicle(AUV) is a robot which can be used for the research on the ocean life and ocean observation in the underwater environment. The traditional AUV with screw propeller has low capabilities of propulsion and low maneuverability. With the development of bionics, the fish-like submarine propeller is researched by the scientist, which is found to have more advantages than traditional propeller, and become a hot topic in the field of robotics. Depends on the Self-Planned Task of State Key Laboratory of Robotics and System (HIT), the basic theory of fishlike robot with tandem flapping wings is developed.The research shows that the fish can improve their swimming performance by catch the energy in the water surround. On this basis, the writer carries out a simulation on the AUV with tandem flapping wings, and tries to increase the thrust and efficiency.First, the paper attempts to model a wing according to the caudal fin of tuna, and simulates it numerically by using CFD computational software Fluent, analyzes the vortex shed by the wing. Then, the writer makes a detailed calculation for the hydrodynamic characteristics of flapping wing whose motion is controlled by different parameters, and the flow structure is also extracted to reveal the reasons for changes in performance. All of this determine the range of parameters for the flapping wing in high performance.The hydrodynamic interactions between two tandem foils are investigated numerically in this paper. The simulations indicate that vortex structures shed by the upstream wing can increase the thrust and efficiency of the downstream wing. however, this augmentation is found to be must in the specifically condition, which depends on the motion and space between the two wings. The current simulations try to find a better condition that the wings can provide higher better performance.In this paper, the method of CFD numerical simulations are used to analyze the effect that vortex, shed from one flapping wing, have on the thrust of itself and another flapping wing placed downstream. All of these would provide the reference for the design of underwater vehicle based on flapping propulsion.