Research On Wind Shear Detection Method And Characteristic Analysis Of Lanzhou Zhongchuan Airport

Wind-shear is the number one killer that threatens the flight safety and efficiency in plateau areas.Encountering wind shear during aircraft climbing and landing will seriously affect the aircraft balance,and even cause serious flight accidents.With the rapid development of civil aviation in China and the increase of flight volume,the impact of wind shear on civil aviation transportation is increasing.Revealing the characteristics of the wind shear in the plateau region has important guiding significance for the study and prediction of the wind shear of aircraft on the plateau route.In this thesis,the lidar data of Lanzhou airport in China are used.Firstly,the basic data are processed to eliminate noise and fill in missing measurements,then the wind shear is identified by least square fitting,and the warning area is designed according to the actual operation conditions and requirements of Lanzhou airport.The force analysis of aircraft in actual operation is carried out to calculate the impact of wind shear on aircraft lift.At the same time,a typical case is used to analyze the characteristics of low-level wind shear in Lanzhou,and the following conclusions are obtained:(1)According to the force analysis of the aircraft during level flight,take-off and landing,the force changes of the aircraft in downwind shear,upwind shear and crosswind shear are analyzed on the above basis.The change degree of the aircraft lift after encountering downwind shear,upwind shear and crosswind shear of different intensities.(2)The "K-Neighborhood frequency method" can remove noise and fill in missing values from the wind lidar data.The optimal parameters can be obtained by comparing multiple groups of experiments.After quality control,the authenticity of the data can still be guaranteed to ensure the next step.The least square linear fitting is used to effectively identify the low-level wind shear,and the low-level wind shear early warning threshold and key monitoring areas are designed according to the aircraft takeoff and landing safety standards and the actual operation of the airport.(3)According to the characteristic analysis of 39 cases of wind shear data of Lanzhou airport,the low-level wind shear of Lanzhou Zhongchuan airport mainly occurs in the afternoon and evening,which is due to the downward momentum at noon,the increase of ground heating effect,the strengthening of convection and the increase of wind speed.Among them,it occurs the most in June,accounting for 33.3%.The aircraft is affected by wind shear during landing.Lanzhou airport wind shear is easy to occur under convective weather.Grasping the characteristics of convective weather is the basis of low-level wind shear prediction in Lanzhou.