Aircraft Wake Vortex Evolution and Decay in Idealized and Real Environments: Methodologies, Benefits and Limitations Advances in LES of Complex Flows

After a brief introduction of the governing equations and numerical approaches that are used to simulate wake vortices in the atmosphere associated implications and restrictions are discussed. The complex interaction of turbulence and rotation in the vortex core region is not resolved appropriately and is controlled by the subgrid scale model. A local Richard-son number correction for strong streamline curvature effects is proposed that accounts for stabilizing effects of coherent rotation and reduces vortex core growth rates. Real case simulations demonstrate that LES is capable to reproduce complex wake vortex behaviour as the spectacular rebound observed at London Heathrow Int’l Airport. Various idealized cases with stably stratified, turbulent and sheared environments are used to reveal the mechanisms thatcontrol vortex decay.