An aircraft carried by air always leaves behind it a wake consisting of vortices, the power of which increases with the mass of the aircraft. In this plan perpendicular to the aircraft path, the largest vortices were generated at the wingtips. The slats and flaps deflected in takeoff phase are the source of the smallest structures.
copyright © ONERA 1996-2006
Numerical simulation of transport aircraft wake vortices
(DSNA - Odile Labbé)
copyright © ONERA 1996-2006 - Tous droits réservés Simulation numérique des tourbillons de sillage d'un avion de transport (DSNA - Odile Labbé)
The mass of air placed in rotation is very large and the induced velocities can be as much as 30 m/s, which would destabilize an aircraft crossing them and even cause it to fall. It is the mixture of these vortices with the jets from the turbojets that create the contrails we can observe in the sky.
These vortices are harmful around airports because they require the aircraft to keep a very large safety distance between them. As they are invisible under normal conditions, they are difficult to study. Numerical simulation makes it possible to understand their mechanisms, test their sensitivity to atmospheric conditions, assess specific measures for reducing their impact, etc.