富勒襟翼外形的参数化建模及优化

富勒襟翼能够产生比普通单缝襟翼更大的升力增量,而且比双缝和多缝襟翼结构简单、活动部件少,更有利与气动优化,在现代民用飞机上有着越来越多的应用。本文使用二次曲线分段构造富勒襟翼的几何外形,使用SST-k-ω湍流模型对气动网格模型进行数值模拟,以此为基础优化襟翼的几何外形来提高襟翼的升力增量,并对襟翼外形优化前后的计算结果进行了分析。研究结果表明,通过优化富勒襟翼外形,可以提高襟翼头部的吸力峰值,进而提高对主翼环量诱导作用,使得两段翼型的升力系数增加。基于CFD流场显示,可以发现由于襟翼缝道流动对襟翼气流的分离起到抑制作用,因此随着两段翼型迎角的适当增加,反而可以改善襟翼上方气流的分离情况。

Design and Optimization of Fowler-Type Flap

Fowler-type flap provides higher lift increment than common single slotted flap,and it is more simple than double slotted flap in structure and motion mechanism,which makes it easier to optimize the lift increment of flap,so it has been applied widely in modern commercial transports.In this paper,conic curve is used to model shape of flap,and the aerodynamics gird is simulated by SST-k-ω turbulent model.Base on simulation results,lift of two-element airfoil is improved by optimizing sharp of flap.The differences of airfoils＇ lift are studied by comparing the numerical simulation results.The result of study shows that,the suction peak of flap is enhanced by optimizing shape of flap,which increases induction to main foil＇s circulation,leading to the increase of lift coefficient of two-element airfoil.Flow field by CFD show that,main foil＇s wake flow and slot flow inhibits flow separation of flap.So when attack angle of airfoil increases,flow separation of flap decreases.