Study On Dissipation Mechanism And Intervention Methods Of Aircraft Wake Vortex

In order to control and avoid the adverse effects of aircraft wake on aviation safety and air traffic operation efficiency,and to provide a theoretical basis for reducing the wake separation,it is necessary to study wake vortex movement and dissipation mechanism.Firstly,to study wake vortex intensity dissipation and movement in ground proximity,Reynolds average simulation method and large eddy simulation method were applied to carry out vortex numerical simulation experiments respectively.The variation rules of vortex trajectory,vortex velocity and circulation were analyzed.The results show that,when wake vortex was in ground proximity,its intensity decreased continuously,vortex separation increased gradually,and the mutual induction effect was weakened gradually.The secondary vortex was detached from the boundary layer of ground surface,which would lead the wake vortex to rebound quickly.Moreover,it was found that the large eddy simulation method has better effect,higher accuracy and better agreement with engineering practice.Secondly,the large eddy simulation method was applied to study the wake vortex movement and dissipation rules under the crosswind of 2m/s and 5m/s.It was found that the shear of the crosswind turbulence lead to the severe fluctuation of vortex,which was strong enough to induce the distortion of the upwind vortex,causing the reconstruction of the velocity field,accelerating vortex decay.Finally,the artificial disturbance vertical plate was established at the end of airport runway.Active artificial intervention was carried out to analyze the effect of wake vortex motion and dissipation.The results revealed that artificial plate could effectively weaken the turbulent kinetic energy of vortex,destroy vortex structure,induce secondary vortex to detach from the primary vortex,as well as triggering the Rayleigh-Ludwieg intersecting instability.Increasing the height of the plate was beneficial to promote the secondary vortex system to roll up and develop as well as the acceleration vortex intensity decay,the vortex circulation decay rate was raised up 17%.