三角翼跨声速动态失速与涡破裂特性研究

通过数值方法研究了高速气流中细长三角翼作匀速上仰机动飞行时的背风面分离流与涡破裂特性和气动力特性。结果表明，在三角翼匀速上仰非定常绕流中，涡破裂起始攻角与上仰速度关系比较复杂，在本计算速度范围内，涡破裂起始攻角变化很小；动态时涡破裂点发展速度随攻角变化规律与静态结果差别甚大；三角翼大攻角非定常绕流前缘涡涡轴附近的流动以不稳定涡和涡破裂为主要特征；在一定的上仰速度以后即使在中等攻角前非定常升力与定常升力仍有较大差别，与低速情况有所不同；上仰运动使涡破裂点发展速度被延缓，从而提高了失速攻角和最大升力，并使失速攻角与涡破裂起始攻角的间隔进一步拉大，同时不改变升阻比

THE STUDY OF TRANSONIC DYNAMIC STALL AND VORTEX BREAKDOWN OVER A DELTA WING

The transonic separated flows around a pitching delta wing and vortex breakdown and aerodynamics characteristics are studied numerically. The results show that, the starting angle of attack of vortex breakdown is related to pitching speed very complicatedly, but doesn't change much in present calculation. The development of the bursting point in dynamic cases is very different from that in stationary cases. The unstable vortex and vortex breakdown are the main features of unsteady flow near the core of leading edge vortex around a delta wing at high incidence. When the pitching speed is high enough, the unsteady lift will higher than steady lift even at middle incidence, which will don't occur in incompressible cases. The pitching movement increase the stalling angle of attack, maximum lift and the lag between stalling and bursting angle of attack due to the vortex breakdown is delayed, but almost doesn't change the C L /C D .