同向旋转涡对融合机理的数值模拟研究

飞机起降过程中,翼尖涡和襟翼涡相互作用,形成同向旋转的涡对。它们相互诱导同时向上卷起,并逐渐融合成为一对尾涡。尾涡对后面飞机的安全飞行有非常大影响,并且直接关系到机场航班数量。通过研究涡对融合的机理,可以预见甚至控制涡对融合的位置以及尾涡耗散。采用大涡模拟方法对同向旋转涡对融合机理进行了研究。分析了从涡丝生成到涡对融合的过程,并给出了不同平板间距及不同迎角下,涡对融合距离的非线性特性,计算结果与试验结果进行了比较,认为两者相符很好。

NUMERICAL STUDY ON MERGING MECHANISM OF CO-ROTATING VORTEX PAIR

Co-rotating vortices are generated with the deployment of flaps when aircrafts are taking off or landing. The flap vortices and the tip vortices interact with each other and also influence themselves as they roll up. Then they merge together to form a pair of trailing wakes as they flow down stream. The vortex wake is very dangerous for the following aircraft. Wake vortices also influence and limit the capacity of airports. Hence the mechanism of co-rotating vortices mergence is of great importance. It can be used to predict even control of merging location and vortex dissipation. The merging mechanism of co-rotating vortex pair is numerically simulated using large eddy simulation, the nonlinear merging process at different separating distance and different angles of attack are analyzed, and the results are in good agreements with the experimental results.