Abstract: In order to meet the design requirements of high lift system with high efficiency and simple structure for modern large aircraft, this paper selects a typical three element airfoil, and, based on numerical simulation, studies the feasibility of mini-trailing edge device (mini-TED) to improve the aerodynamic performance of the lift system and analyzes its physical mechanism and the impact of its geometrical parameters, including the mini-TED fixing position, length and deflection angle. The study shows that the mini-TED changes the curvature of the trailing edge and increases the effective aerodynamic chord length for a high lift system, acting like an additional aerodynamic flap. Mini-TED with geometrical parameters of length l≤1.5%c (c is the chord length) and fixing position before 95% length of the flap is suitable, and its deflection angle can be adjusted based on different flying states. Compared with the four or more element high lift system, mini-TED features remarkable lift enhancement effect, simple structure, light additional height, and easy application in engineering. It possesses attractive potential as a new lift enhancement technique.

Key words: high lift system, mini-TED, numerical simulation, geometrical parameter, physical mechanism, design principle