Study On The Risk Of Aircraft Wake Encountering In Approaching Stage

Aircraft wake is the cause of keeping the safe interval of aircraft sequence.Safe wake interval contributes a lot to ensure the order and safe operation of flights,but at the same time,it also limits the improvement of capacity to a certain extent.We have done much research on classification,formation and evolution mechanism of aircraft wake,its impact on the rear aircraft,the selection of risk assessment indicators for aircraft wake encounter and the evaluation of severity indicators for aircraft wake encounter.On the basis of relevant research at home and abroad,the wake model is established,the influencing factors of the initial wake circulation are analyzed,the distribution of wake circulation on the wing span with different airfoils is studied,the induced velocity model is established,and the wake induced velocity field is simulated;based on three wake encounter scenarios,we have established three wake encountering models which are the dynamic response of aircraft crossing the wake,the dynamic response of longitudinal encountering single vortices,and the dynamic response of longitudinal encountering double vortices.The risk assessment index of wake encounter is selected by data analysis method.The risk assessment index of wake encounter is analyzed by factor analysis and structural model analysis by using software including AMOS and SPSS.Finally,the induced roll moment is proved to be the evaluating indicator of the severity of aircraft wake encounter.Referring to the flight simulation experiment data of ICAO wake encounter,the calculation method of induced roll moment coefficient proposed in this paper is compared with Euro-controll’s method.It is proved that the method used in this paper is safe and reliable,and can be used in the development of wake encounter risk assessment tool and the safety analysis of wake interval reduction.A wake encounter severity assessment system is established to evaluate the safety of the current wake interval based on the severity of the wake encounter.Aiming at the safety assessment of the current wake interval,the values of residual wake circulation and induced roll moment coefficient are proposed.It can be used as the safety level value of wakeinterval risk assessment and the development of wake interval risk control tools.Wake separation standards play an important role in flight safety and efficiency,although the existing standards play an important role in ensuring air traffic safety and orderly operation of aircraft.However,the law of wake dissipation and transport varies greatly with different meteorological conditions,and the existing standard of interval is too conservative in most meteorological conditions.Excessive wake interval standard increases the interval between takeoff and landing aircraft,limits the capacity of controlled airspace to a certain extent,and affects the utilization efficiency of airport resources.The study of aircraft wake encounter risk is the key work of dynamic wake interval operation and even optimization of current wake interval,which must be carefully studied.This paper studies the formation and evolution of wake and its impact on the rear aircraft,establishes a risk assessment model of aircraft wake encounter when approaching,puts forward an evaluation index of aircraft wake encounter severity,and validates the index.The research results will provide a theoretical basis and experimental basis for the development of more scientific wake spacing standards,improve the utilization efficiency of airport runways,and provide reference for the development of more optimized aircraft entry and exit operating standards.