Analysis of the Impact of ADHF Configuration on Flap Parameters Optimization for Civil Aircraft

Using computational fluid dynamics method, numerical simulation is carried out on the typical two-dimensional multi-segment wing with the deflection hinged flap configuration of spoiler. The study investigated the optimization of gap size for the deflected flap under spoiler, and attempted to analyze its underlying mechanisms. The results indicate that within the scope of this study: 1) the deflected flap configuration can significantly increase lift at small angles of attack, with the lift enhancement gradually decreasing as the angle of attack increases; 2) the ADHF alters the conventional optimal gap size design selection, where appropriate deflection with spoilers can decrease the local angle of attack of the flap, shift the stall point towards the upper surface, counteract the effects of increased gap size, and thereby expand the range of gap size selection, thereby improving the lift coefficient in the near-stall regime to some extent.