翼型近波浪水面气动特性研究

The aerodynamic characteristics of NACA 4412 airfoil moving over wavy water at small clearance is studied by solving Navier-Stokes equations. The accuracy of the numerical method is verified. The aerodynamic coefficients of airfoil moving over wavy water surface and wavy ground are calculated and compared. The results show that the aerodynamic coefficient changes periodically when the airfoil moves over the wavy water surface. Compared with the case of wavy ground, the variation curve of aerodynamic coefficient is significantly different and the fluctuation amplitude is larger. Through the analysis of the flow field structure, the interaction mechanism between the airfoil and the wavy water surface is found. The particles on the wavy water surface have vertical motion, when the clearance is small, the upward movement of the particles on the water surface will squeeze the air between the airfoil and the water surface, resulting in a large fluctuation of the airfoil aerodynamic force. At the same time, the reason why the fluctuation amplitude of aerodynamic coefficient decreases with the increase of incoming flow velocity is explained.