Tech Talk: McLaren's radical wavy rear-wing
McLaren managed to rush its Hungarian Grand Prix developments through earlier and get them on the car for the German GP weekend which helped Kevin Magnussen to qualify fourth on the grid.
The rear-wing is the most noticeable change and looks rather radical when compared to rival cars.
The wing features small turning vanes on the endplate (see arrow 1) to help airflow travel upwards to the wing tip, reducing the vortices that are created as the air spirals off edge and therefore reduces drag.
The more unusual development though is to the main plane and flap (see arrow 2). The trailling edge of the main plane and the leading edge of the flap are serrated.
This isn't a new concept and was used back in 2004 by BMW and is often seen in Le Mans.
The idea is to create lots of small vortices - these come off the top of the waves - and travel up the rear-wing flap when it's closed, reducing the risk of airflow separation.
They're also important when DRS is in use, or more importantly when the driver has just pressed the brake and the flap has returned to the closed position.
It can often take a couple of seconds for the airflow to re-attach itself to the flap - by that time the driver has entered a corner and is depending on the rear-wing to provide downforce. It won't do so effectively if the airflow is scattered.
The vortices coming off the wavy edge should help to re-attach the airflow far quicker and more efficiently than a straight trailing edge would do, therefore providing rear-end stability through the corner following use of DRS.