Numerical Simulation of Continuous Morphing Wing with Leading Edge and Trailing Edge Parabolic Flaps

Abstract

The present study numerically investigates the aerodynamic performance of the morphing airfoil and wing with leading edge (LE) and trailing edge (TE) parabolic flaps. Reynolds-averaged Navier-Stokes (RANS) equations coupled with the Spalart-Allmaras (S-A) turbulence model are employed to simulate the flow fields. Firstly, the parameterization method for the morphing airfoil with LE and TE parabolic flaps is proposed. Secondly, the influence of several design parameters, namely, LE droop angle, LE droop position, TE deflection angle, and TE deflection position, on the airfoil aerodynamics are further explored. Moreover, the aspect ratio (AR) effect for the wing based on the morphing airfoil is also investigated. Simulation results demonstrate that the parabolic flaps outperform the articulated flaps in lift generation, drag reduction, and aerodynamic efficiency enhancement, with an improvement in CL and L/D by 39.2% and 108.4% at α=4°, respectively. A larger LE droop angle can increase the stall margin, whereas the LE droop position barely influences airfoil aerodynamics at small angles of attack. The increment of the TE deflection angle significantly augments the lift. As the TE deflection position moves downstream, the suction peaks at the LE and TE are decreased and flow separation is also delayed. Furthermore, a larger AR can achieve higher efficiency, whereas a smaller AR is more beneficial for flow separation suppression.