| The shield scale structure of shark skin surface can reduce the resistance.In this paper,a three-dimensional model of bionic surface structure is constructed based on the bionic principle.Based on the numerical calculation and test method,the hydrodynamic characteristics of the bionic surface structure are studied.The bionic surface structure is applied to the hydrofoil and the rotating cylinder to study the influence of the bionic surface structure on the hydrodynamic characteristics of the hydrofoil and the rotating cylinder.Firstly,biomimetic modeling of shark skin surface microstructure is carried out,and the flow field characteristics of a single surface structure are studied by numerical method.Analyze and simplify the micro structure shield scale of shark skin surface,extract the main shape parameters,and complete the modeling of bionic surface structure;use numerical simulation method to study the flow characteristics of bionic surface structure,place the bionic surface structure on the plate,use numerical calculation software to simulate the flow field of bionic surface structure,and get the resistance characteristics and velocity cloud with bionic surface plate The flow characteristics of the bionic surface structure are studied in comparison with the smooth plate;Secondly,the bionic surface structure is applied to three-dimensional airfoil and cylinder,and the influence of bionic surface structure on lift resistance and flow field characteristics of hydrofoil and rotating cylinder is studied by numerical calculation method.A series of bionic surface structures are arranged in the specific position of the suction surface of NACA0012 three-dimensional hydrofoil.The lift resistance performance and flow field of the three-dimensional airfoil at different angles of attack are calculated by using numerical simulation method.The influence of bionic surface structure on the hydrodynamic performance of the three-dimensional airfoil is explored by comparing with the smooth NACA0012 airfoil.The study of the influence on the cylinder can be divided into two cases:short cylinder and long cylinder.The short cylinder is a common smooth cylinder,and the long cylinder is a special cylinder with a groove at the bottom.The bionic surface structure is covered with the outer surface of the cylinder.The influence of the bionic surface structure on the lift resistance and hydrodynamic characteristics of the rotating cylinder is explored by comparing with the smooth cylinder;finally,carry out experimental studies on airfoils and cylinders,use force balance to measure the change of lift and resistance,and use PIV device to measure the flow field.The 3D airfoil and cylinder models are processed by 3D printing method,and the hydrodynamic tests of airfoil and cylinder were carried out in the water-circulating channel.In the airfoil test,the accuracy of numerical simulation is verified by selecting specific attack Angle and flow velocity conditions.The cylinder experiment is conducted to explore the force and flow field of the cylinder at different flow rates,which is verified by numerical simulation,and the influence of bionic surface structure on hydrodynamic characteristics of the rotating cylinder was further investigated.Based on the research of bionic surface structure by numerical calculation and experimental method,the flow characteristics of the bionic surface structure are analyzed,and the influence of the bionic surface structure on the hydrodynamic characteristics of airfoil and rotating cylinder is analyzed by numerical calculation and experimental analysis. |
PDF Full Text Request