Study on the Influence of a Wake Vortex on an ARJ21 Aircraft Using the Strip Method

A model for the vortex distribution in the wake of an aircraft is elaborated to investigate the wake influence on the behaviour of other aircrafts potentially interacting with it.As a realistic case,the interaction of an ARJ21 aircraft with a(leading)A330-200 aircraft is considered.Different distances are considered,namely,6 km,7 km,8 km,9.3 km,and 10 km.Simulations based on the used wake dissipation mechanism are used to investigate different conditions,namely,the ARJ21 in take-off and level flight and the changes induced in the related lift by the front aircraft A330-200 during landing.The induced roll moment is also studied and analyzed by means of a strip method.As a result,the roll moment coefficient is determined to quantify the roll degree of the aircraft when it is influenced by the wake vortex.The results show the overall roll moment coefficient of the considered ARJ21 aircraft is less than 0.05,and the wing roll moment coefficient is less than 0.04.Such results are interpreted and discussed according to existing standards.

Automatic interval management for aircraft based on dynamic fuzzy speed control considering uncertainty

A novel real-time autonomous Interval Management System(IMS)is proposed to automate interval management,which considers the effect of wind uncertainty using the Dynamic Fuzzy Velocity Decision(DFVD)algorithm.The membership function can be generated dynamically based on the True Air Speed(TAS)limitation changes in real time and the interval criterion of the adjacent aircraft,and combined with human cognition to formulate fuzzy rules for speed adjusting decision-making.Three groups of experiments were conducted during the en-route descent stage to validate the proposed IMS and DFVD performances,and to analyze the impact factors of the algorithm.The verification experimental results show that compared with actual flight status data under controllers’command,the IMS reduces the descent time by approaching 30%with favorable wind uncertainty suppression performance.Sensitivity analysis shows that the ability improvement of DFVD is mainly affected by the boundary value of the membership function.Additionally,the dynamic generation of the velocity membership function has greater advantages than the static method in terms of safety and stability.Through the analysis of influencing factors,we found that the interval criterion and aircraft category have no significant effect on the capability of IMS.In a higher initial altitude scenario,the initial interval should be appropriately increased to enhance safety and efficiency during the descent process.This prototype system could evolve into a realtime Flight-deck Interval Management(FIM)tool in the future.