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采用经风洞试验验证的CFD计算方法和网格生成策略,研究某大型民用运输机着陆构型纵向失速特性的改善措施,将全机分为七大部件:机身、内翼段、中翼段、外翼段、翼梢、短舱和平尾,分别分析各部件的影响。研究结果表明:内中翼段对全机俯仰力矩曲线上拐的贡献为负,恶化其气动性能可以在一定程度上改善全机力矩特性,但是与此同时会降低最大升力系数和失速迎角;翼梢小翼在低速大迎角时发生大面积分离,对全机俯仰力矩曲线上拐的贡献为正,修形后构型的翼梢前缘产生很强的空间涡,很好地抑制分离区的产生和发展,改善了全机俯仰力矩特性,但是简单的翼梢修形会增大巡航时的诱导阻力,需要在高/低速之间进行权衡;平尾对全机俯仰力矩曲线上拐的贡献为正,其中内襟翼翼根涡对平尾当地来流的影响最为显著,通过修形整流包可以很好地解决这个问题,使全机俯仰力矩曲线上拐迎角增加4°。
The CFD calculation method and grid generation strategy verified by wind tunnel test are used to study the improvement measures of the longitudinal stall characteristics of the landing structure of a large civilian transporter. The whole machine is divided into seven major components: fuselage, inner wing section, middle wing section , Outer wing segment, wing tip, nacelle and horizontal tail, respectively, the impact of each component analysis. The results show that: the inner mid wing section contributes to the uphill turning moment of the whole machine pitch negative curve negatively. Decreasing its aerodynamic performance can improve the whole machine moment characteristics to some extent, but at the same time it will reduce the maximum lift coefficient and stalling angle of attack; Winglets at large low angle of attack at a large area of separation, the whole pitch and pitch curve of the contribution to the turn on the positive, the modified shape of the tip of the tip of the wing to produce a strong space vortex, well suppressed separation The emergence and development of the zone improve the pitch moment characteristics of the whole machine. However, simple wing tip modification will increase the inducing resistance during cruising and need to be weighed between high and low speeds. The contribution of the internal flap wing root vortex to the local tail flow is the most significant. By rectifying the rectification package, this problem can be solved well, and the angle of attack angle on the whole pitching moment curve can be increased by 4 °.