Simulation of Aircraft Wake Vortices During Landing with Decay Enhancing Obstacles

Abstract

Wake-vortex evolution during landing of a long range aircraft is investigated in a turbulent environment. The simulations cover final approach, touchdown on the tarmac, and the evolution of the wake after touchdown. An ambient turbulent crosswind and headwind field is generated in a pre-simulation. The wake is initialized using a RANS-LES coupling approach. The aircraft in high-lift configuration with deployed flaps and slats is swept through a ground fixed domain. The fuselage turbulence is modeled as white noise. The further development of the vortical wake is investigated by large-eddy simulation until final decay. After touchdown wake vortices are subjected to strong three-dimensional deformations and linkings with the ground. The downwind vortex is strongly advected with the wind and decays quickly. End effects, appear after touchdown and propagate along the wake vortices against the flight direction. They lead to a non-uniform circulation decay of the rolled-up wake vortices. Additionally the effect of a plate line installed in front of the runway is studied with this method. The plates cause disturbances of the vortices propagating to either side and interacting with the end effects. The plate line further accelerates the vortex decay.