飞机进入前机尾流区将生俯仰、滚转、失速等影响安全的现象。近地阶段的飞机尾流会对后机的飞行安全产生更加严重的影响，而过大的飞行尾流间隔又会限制机场跑道资源的高效利用。本课题拟对近地阶段飞机尾流演化机理和飞行风险控制方法开展系统性的研究。在课题组前期尾流探测和实验历史数据基础上，采用数值方法对飞机尾流的形成、发展和消散进行理论研究，再进行风洞实验进行尾流演化机理的研究，通过基于尾流特征参数、尾流失稳过程和尾流诱导及其与二次涡的相互影响，揭示近地阶段飞机尾流演化机理。考虑近地阶段飞机飞行高度和飞行速度不断变化的特点，研究不同跑道构型下的飞机近地阶段碰撞风险模型；然后，根据实际和理论数据确定尾流间隔标准安全评估指标，对近地阶段飞机尾流间隔缩减进行安全性分析；最后提出近地阶段飞机尾流间隔动静态标准建议。课题研究成果将为制定更科学的尾流间隔标准、提高机场跑道利用效率提供理论基础和实验依据。

Flight safety issue, such as pitch, roll and stall, would arise when the following aircraft flies into the wake vortex caused by the former aircraft. Such safety issue is more severe especially for aircraft in the near-ground stage. However, too excessive wake separation would limit the utilization efficiency of runways. So, this project focuses on processes of the aircraft wake vortex during the near-ground stage, and its related flight risk control strategies. The numerical simulation method will be applied to investigate the formation, development and dissipation of the wake vortex based on the historical wake vortex detected datasets and experimental datasets. The complex flow of wake vortex will be analyzed by conducting wind tunnel experiments, and the mechanisms of the wake vortex evolution for the approaching plane will be revealed based on the characteristic parameters of the wake vortex, the vortex instability process, the wake vortex inducting and its interaction with the secondary vortex. The aircraft collision risk model is expected to be established for different runway configuration by considering the elements of the constant changing flight altitude and velocity. The safety evaluation index system can be further established to analyze the safety of the wake separation reduction for the aircraft in near-ground stage. Finally, the dynamic and static criteria of the aircraft wake separation will be made respectively. Research of this project can be served as the theoretical and experimental basis for establishing a scientific wake separation standard, and it can also be regarded as a robust reference for the decision-making of the highly efficient runway utilization.