大迎角下机翼后掠角对近耦合鸭式布局增升及流态的影响

Effects of wing sweep on lift-enhancement and flow patterns of close-coupled canard-configurations at high incidence

在风洞中利用测力及油流显示技术对不同后掠三角鸭翼和不同后掠三角机翼构成的鸭式布局在大迎角时的增升及流态特征进行了研究。通过测力给出了机翼后掠角对近耦合鸭式布局升力系数增量在大迎角时的影响规律,并通过油流显示对其影响的机理进行了探讨和分析。研究表明,鸭式布局是否增升受迎角和机翼后掠角的共同影响。在研究的迎角范围内的特定迎角下,与小后掠机翼构成的鸭式布局相比大后掠机翼构成的鸭式布局具有更好的增升效果,原因在于小后掠三角翼前缘涡随迎角变化时易于破裂,鸭翼对破裂涡,特别是完全破裂涡流态有较好的改善作用。

An experimental wind-tunnel investigation was undertaken to determine the characteristics of lift-enhancement and oil-flow patterns of close-coupled canard-configurations with different sweep delta-wings and delta-canards. The results of lift-measurement revealed the effect of wing sweep on lift-enhancement of close-coupled canard-configurations, and the flow visualization further interpreted the flow mechanism of lift-enhancement. It can be found that the lift-enhancement is substantially affected by the wing sweep and angles of attack. At certain angle of attack, the lower sweep wing has better effect of the lift enhancement than the higher ones. From oil-flow patterns, it can be found that the leading-edge vortex of low sweep delta-wing was prone to breakdown and the canard can promote flow patterns when the leading-edge vortex of delta-wing breakdown.