Research On The Reduction Of Wake Vortex Separation Based On Tip Blowing Technology

It is the key to ensure the operational efficiency of the terminal area and the safety of the rear aircraft to have a reasonable wake spacing for the front and rear aircraft when the aircraft is in the approach phase.By making the reduction of wingtip vortices a design objective,the wake spacing can be significantly reduced from the existing base.Using numerical simulations,this paper evaluates the change in wingtip vortex strength by adding jet vents to the wingtip to influence the generation phase of the wingtip vortex and,based on this,quantitatively analyzes its impact on the current wake spacing criteria.The numerical simulation results show that the vortex system of the rectangular wingtip differs from the point vortex structure of the circular wingtip rolled up from the lower edge of the wing due to the presence of the fold angle,including three forward vortices with the same direction of rotation as the main wingtip vortex and two small-scale reverse vortices with irregular shapes.Fragmentation and fusion between different vortex systems further reduce the amount of wingtip vortex ring during the backward evolution of the flow field and the roll-up.After determining the characteristic position directly below the primary vortex system at 0.8times the chord length,four configurations were obtained and numerically simulated by adding jet jets at the leading and trailing edges of the upper and lower surfaces of this position.The results show that the jet nozzle at the trailing edge of the upper surface of the wing has the best effect on the reduction of the wing tip vortex ring volume,which induces the energy consumption of the reverse vortex system and primary vortex in the process of wing tip vortex generation,and reduces the overall rotational capacity inside the ring volume while inducing the reduction of the vortex core vortex volume.The vortex volume in the X-axis is reduced by7.69%.The jet nozzle at the trailing edge of the wing is more conducive to the reduction of wingtip vortex ring volume among the four configurations.In this study,the maximum ring volume that the rear aircraft can withstand is determined as an indicator to study the wake spacing.The author selected seven typical aircraft types from A to G under the ICAO standard,and used the APA wake vortex dissipation model to calculate the decay process of the ring volume with time when the typical aircraft type is the front aircraft;and used the strip method to calculate the maximum ring volume that the rear aircraft can withstand under different roll moment coefficient(RMC)critical values when the typical aircraft type is the rear aircraft.The final tail flow interval of the aircraft under different RMC critical values was obtained.After comparing with the ICAO RECAT wake interval,the RMC value of 0.031 was selected as the typical roll moment coefficient for studying the wake response of the aft aircraft.The simulation results show that this critical value can significantly reduce the wake interval criteria while ensuring the safety margin.The paper concludes by adding the jet nozzle effect designed based on the numerical simulation results to each typical aircraft,with the exception of the minimum radar spacing required for radar control equipment,the wake spacing reduction for mainstream passenger aircraft reaches more than 25%.It provides an effective idea to improve the control efficiency in the terminal area of busy airports,reduce the cost of airlines,and reduce the overall carbon emission target.