旋成体导弹小展弦比舵面大偏度对称状态下非对称流动机理

针对跨声速条件下，小展弦比截尖三角翼尾舵的旋成体导弹在小迎角、零侧滑、大舵偏对称状态下呈现出的非对称流动现象，本文首次对其进行了分析研究。首先，通过一系列测力试验、表面油流试验及粒子图像测速（PIV）试验对该非对称流动现象进行了精准捕捉，并对其产生的原因进行了分析。然后，基于已获得的试验数据及流场观测结果，借助数值模拟方法对所述非对称流动的细节、拓扑结构、空间形态及舵面压力分布等问题做了深入研究，并进行了详细讨论。结果表明：旋成体导弹小展弦比舵面大偏度对称偏转时，舵面前缘产生的翼尖涡会因舵面相距较近而相互干扰，促使翼尖涡沿流向非对称发展，使得舵面压力分布不均，最终导致非对称流动和较大横向量的产生，影响导弹的气动性能。

Asymmetric flow mechanism for small aspect ratio rudders with large deflection angles on rotated missile

In transonic wind tunnel test, regarding the problem of the asymmetric flow over a slender body of the low aspect ratio and a cutoff-delta wing tail vane in the symmetric states of small angle of attack, zero sideslip angle and large rudder angle, a series of force test, oil-flow and particle image velocimetry (PIV) test has been launched and analyzed. Based on the test data and observation of flow field, the details of the asymmetric flow, topological structure and spatial form have been studied and discussed in detail by numerical simulation. The results show that when a slender body with a low aspect ratio of control surface has large symmetric deflection angle, the wingtip vortex generated by the leading edge of control surfaces will interfere mutually for the close range between them, which would make the wingtip vortex go asymmetrically along the flow and the pressure of control surfaces maldistribution. Finally, it would lead to asymmetric flow and large yawing force over the slender body, which would affect the aerodynamic performance of a missile.