基于相干多普勒激光雷达的飞机尾涡观测

Observation of Aircraft Wake Vortex Based on Coherent Doppler Lidar

相干多普勒激光雷达(Coherent Doppler Lidar,CDL)凭借高精度、高时空分辨率等优势已成为晴空尾涡探测的主要手段。为了提高飞机尾涡观测效率并实现数据的快速处理和实时显示,基于2018年在四川开展的尾涡观测实验,提出了一种基于CDL频谱宽度和径向风速的尾涡快速识别方法,并基于此方法分析了典型机型的尾涡演化过程。结果表明,不同机型的尾涡演化趋势相似,均在距地面约50 m处产生并向下、向外扩散,尾涡环量逐渐减小,但由于近地面效应的影响,会伴有短时间环量增加现象。随着飞机重量和翼展的减小,尾涡的耗散时间缩短,左右涡初始涡核的间距减小,频谱宽度融合现象更明显,该现象消失所历经的时间增加。

Coherent Doppler lidar(CDL)is frequently used to detect wake vortexes in the clear days because of its advantages of high precision,high spatial and temporal resolution and so on.To improve the observation efficiency of wake vortexes and realize the fast processing and real-time displaying of data,the wake vortex observation experiments were performed in Sichuan province in 2018 and a fast method for identification of wake vortexes was presented based on the radial velocity and spectral width given by CDL.In addition,the wake vortex evolution processes of typical aircraft types were analyzed based on the proposed method.The results show that the wake vortex evolution tendency is similar for all different aircraft types,which first occurs at about 50 m above the ground,then diffuses downward and outward,and the circulation of wake vortexes gradually decreases.However,it is accompanied by the short-time increase of circulation under the influence of the near-ground effect.With the decrease of aircrafts’weight and wingspan,the dissipation time of wake vortexes decreases,the initial distance between the cores of the right and left wake vortexes gets short,the fusion phenomenon of spectral width becomes more obvious,and the time for the disappearance of this phenomenon increases.