Numerical Prediction Of Hydrodynamic Performance Of Bionics Penguin Flapping-foil Propulsion

Flapping-foil marine creatures such as penguins,sea turtles,and sea lions use pectoral fins as the main propulsion organs.The manipulation and control of their postures is achieved by the thrust and lift of the fins,which has high propulsion efficiency.Penguins have graceful streamlined profile that swim fast,underwater fishing is flexible and its excellent propulsion and performance is worthy of in-depth research by researchers.In this paper,through the establishment of the bionics penguin model,the numerical simulation method is used to study the hydrodynamic performance of the bionics penguin flapping-foil propulsion.Firstly,based on the experimental model and experimental data of the US DARPA submarine model SUBOFF,the paper verifies the applicability and calculation accuracy of predicting the hydrodynamic performance of the underwater vehicle based on STAR-CCM+software.Based on this,the bionics penguin model is established and carried out.The stem and stern optimization design,the resistance numerical study of the bionics penguin model,the resistance and drag coefficients of the three models were analyzed,and the shape design of the bionics penguin model was determined.Then,in order to verify the applicability and calculation accuracy of the STAR-CCM+software to predict the hydrodynamic performance of the flapping wing motion,the NACA0012 profile flapping wing experimental model made by Read at MIT was used as the research object,and the two-dimensional wing was adopted by STAR-CCM+software.The numerical study based on the lift-based is carried out,and the influence of Strohal number on its hydrodynamic performance is discussed.The calculation results are compared with the experimental results to verify the applicability of the numerical calculation method.In this paper,the hydrodynamic performance prediction based on lift-based is carried out on the model of the bionics penguin pectoral fin model.The effects of inflow velocity,frequency,pitch amplitude and flapping amplitude on its hydrodynamic performance are discussed.Finally,the paper carried out a numerical simulation study of the drag-based of the bionics penguin pectoral fin model.By designing the pectoral fin motion model,the effects of inflow velocity,frequency,padding amplitude on its hydrodynamic performance were discussed.Through the numerical study on the flipping fins of the bionics penguin based on the lift-based and the drag-based,it is found that the lift-based flapping-fin has higher propulsive efficiency,the maximum is 0.63.