Model of inflatable structure/fluid interaction for variable leading edge

The paper presents the interactive motion equation of inflatable structure in flow. The inflatable structure is used in the technique of a variable leading edge for high lift. The interaction between structure and fluid is a typically aeroelastic problem. The motion equation is obtained through the analytic solution of an infinitesimal element in the discrete membrane. Coupled with Navier Stokes equation, the aeroelastic equation was solved with time-marching methods, and the aerodynamic characteristics of NACA 63-212 airfoil with the inflatable leading edge(ILE) were obtained. From the results, the ILE technique has been applied to significantly increase the stall angle of attack and lift coefficient. The values of stall angle of attack and maximum lift coefficient were enhanced to be 30 percent and 22 percent, respectively. In addition, the deformation of ILE greatly influenced the flow around the airfoil while the elastic coefficient of material was low. The inflatable structure near the suck peak deformed clearly, and this hump could induce the separation in advance.