大型客机后缘铰链襟翼巡航变弯度气动性能数值研究

更高、更快、减阻是飞机设计三大永恒的追求。传统的固定翼飞机在进行优化设计时需兼顾各种飞行条件,寻求一个折中的最优解,而变弯度机翼的概念能有效解决这个问题,符合上述飞机设计的三大追求。着重研究大型宽体客机后缘襟翼刚性变弯度对巡航气动效率及跨声速抖振边界的影响。首先基于下垂式铰链襟翼机构,编制了机构引导下带扰流板联合偏转的后缘襟翼运动仿真程序,以自动生成不同襟翼偏角的巡航构型。在此基础上对巡航构型进行非稳态气动计算,获得跨声速区机翼抖振边界。以该抖振边界作为约束条件,以襟翼偏角、迎角为双变量,获得Cl-K关系图,得到最优升阻比曲线。本文中襟翼偏角变化为0°~±3°,间隔1°;迎角范围为-2°~5°,间隔1°。计算结果表明,变弯度构型较不变弯度构型升阻比有所提高,抖振边界约提高10%;变弯度构型可提高不同设计点的气动效率,实现减阻省油;跨声速区机翼抖振边界的提高扩大了飞行包线,使得飞机能飞得更高、更快。

Numerical study on aerodynamic performance of a large passenger aircraft with trailing edge hinge flap in cruise variable camber

Higher, faster and drag reduction are the three eternal pursuits of aircraft design. In the optimization design of traditional fixed-wing aircraft, all kinds of flight conditions should be taken into account to seek a sub-optimal solution. The concept of variable camber wing can effectively solve this issue, which is in line with the three goals of aircraft design. In this paper, the influence of rigid deflection of trailing-edge devices on cruise aerodynamic efficiency and transonic buffeting boundary of large wide-body passenger aircraft is studied. Firstly, based on the drooped hinged flap mechanism, the combined deflection simulation program of the trailing-edge flap and the spoiler under the guidance of the mechanism was realized to automatically generate the cruising configuration with different flap deflection angles. The buffeting onset of the cruising configuration in the transonic region is obtained by unsteady CFD method. Taking the buffeting boundary as the constraint factor, and the flap deflection angle and the angle of attack as two variables, the CL-K diagram was obtained to make the optimal lift-to-drag ratio curve. In this paper, the deflection angle of the flap varies 0° to ±3° with an interval of 1° and the angle of attack ranges from -2° to 5° with an interval of 1°. The results show that the lift-to-drag ratio of the deflected configuration is higher than that of the configuration without flap deflection, and the buffeting boundary is improved by about 10%. The results show that the aerodynamic efficiency of different design points can be improved by the deflected configuration, so that the drag reduction and oil saving can be realized. The enhancement of the wing buffeting onset in the transonic region expands the flight envelope, making the aircraft fly higher and faster.