柔性后缘自适应机翼气动特性和操纵反效特性的比较分析

COMPARATIVE STUDY ON AERODYNAMICS AND CONTROL REVERSAL CHARACTERISTICS OF ADAPTIVE WINGS WITH FLEXIBLE TRAILING EDGE

对后缘可无缝、连续柔性偏转的自适应机翼进行了二元气动特性和操纵反效特性分析。建立了带柔性后缘自适应机翼模型和带刚性偏转后缘的传统机翼模型,从升阻特性和力矩特性以及操纵效率对它们进行了比较研究。结果表明:在尾缘点偏转位移相同的情况下,柔性后缘偏转所产生升力更大,升阻比更高。但由于升力增量大以及压心后移量大,导致带柔性后缘机翼产生的附加低头力矩也很大。当考虑机翼的扭转刚度后,带柔性后缘机翼会产生较大的低头弹性扭转角,大大降低了操纵效率。相比之下,虽然后缘的刚性偏转使二元机翼增升较小,但产生的附加低头力矩也相对较小。当考虑机翼弹性后,带刚性后缘的传统机翼反效速压更大、操纵效率更高,总的升力增量反而更大。因此,应对后缘中弧线柔性偏转轨迹进行优化设计,或是通过前缘控制面配合偏转来提高带柔性后缘机翼的操纵效率和操纵反效速压。

This paper aims at presenting an investigation into aerodynamics and control reversal characteristics of adaptive wings with seamless, variable camber, flexible trailing edge. Two-dimensional wing models are comparatively studied in terms of lift, moment and control effectiveness. They are configured with a rigid trailing edge and three types of flexible trailing edge based on the concept of rotating ribs. The results of aerodynamic calculation demonstrate that flexible trailing edges provide both a larger lift and lift to drag ratio, as well as a larger negative pitch moment due to the pressure center moving backward. The two-dimensional wing models supported at elastic centre with torsion stiffness are adopted to compare the control effectiveness among different trailing edges. It is shown that the rigid trailing edge has the largest reversal dynamic pressure and the highest lift effectiveness due to the lowest negative pitch moment and it is suggested that the possible approach to improve the lift and roll effectiveness of the adaptive wing with flexible trailing edge is the combination of leading edge and trailing edge control surface.