Hydrodynamic Performance Of Actively Mata-inspired Deformed Foil

With the development of deep-sea strategy,the traditional propeller-based unmanned underwater vehicle has gradually been failed in satisfying the complexity of the research mission.Recently,it is the hot point that designing of the novel unmanned underwater vehicle with high propulsive performance,high maneuverability and low noise.During the cursing process of the aquatic animals,they always can get the high propulsive performance,high maneuverability and low energy-cost based on their special swimming motion.Thus,it is very meaningful for improving the propulsive performance of future unmanned underwater vehicle when we have a good understanding of the mechanism of bio-mimetic and use it into the designing of the unmanned underwater vehicle.Considering the manta of the basic model,the present paper summarizes the previous conclusion and simulate the hydrodynamic performance of manta-inspired active deforming foil using the computational fluid dynamics in detail.From the perspective of the active deforming method,kinematic parameter,geometry parameter,intermittent motion and dualfoils motion,the propulsive performance of manta-inspired active deforming foil has been considered.The main research contents and innovative works can be summarized as follows:(1)Based on the Wave Plate Theory,the hydrodynamic performance of two-dimensional plate has been theoretically studied.Through the comparation between theoretical and numerical results,the reliability of the numerical method has been validated.Depending on the two-dimensional numerical model,the three-dimensional numerical model for computing the hydrodynamic performance of manta-inspired active deforming foil has been constructed.Moreover,the active deforming motion has been achieved and the present model has been validated with various perspectives.(2)Based on the understanding of the morphology and kinematics of real manta,an engineering-used kinematic equation is constructed.The effect of active deforming method and kinematic parameter on the propulsive performance of the manta-inspired active deforming foil has been studied in detail.The force generation and wake structure of the manta-inspired active deforming foil under chord-wise deformation,span-wise deformation and double-wise deformation have been considered,respectively.Moreover,the effect of frequency,amplitude and wavelength of foil's motion on the propulsive performance of the manta-inspired active deforming foil have been considered,and the differences among different active deforming methods have been compared,which reveals the crucial qualitative relationship between the propulsive performance and active deforming method.(3)Studying the propulsive performance of the manta-inspired active deforming foil under different geometry parameters.Given the certain active deforming method and kinematic parameter of the manta-inspired active deforming foil,the effects of the geometry(including plate,prism,pyramid and foil shape),dimensionless size,anti-symmetry shape on the propulsive performance and wake structures of the manta-inspired active deforming foil have been considered,which reveals the qualitative relationship between the propulsive performance and foil's geometry.(4)Studying the effect of intermittent motion on the propulsive performance of the mantainspired active deforming foil.Given the certain active deforming method,kinematic parameter and geometry of the manta-inspired active deforming foil,the effects of the duty cycle on the propulsive performance of the manta-inspired active deforming foil have been considered,and the propulsive performance of foil's continuous motion and intermittent motion has been compared,which reveals the qualitative relationship between the propulsive performance and intermittent motion.(5)Studying the effect of dual-foils motion on the propulsive performance of the mantainspired active deforming foil.the effect of the gap between two foils on the propulsive performance of the manta-inspired active deforming foil has been considered,and the propulsive performance of dual-foils motion and single-foil motion has been compared,which reveals the qualitative relationship between the propulsive performance and dual-foils motion.In addition,a brief study has been performed on the dual foils with the non-zero phase difference to reveal the fluid mechanism of high maneuverability of manta.