Gurney Flap / Trim - F1 Technical Terms

A Gurney flap is so named after Dan Gurney who first applied such a device to the trailing edge of the rear wings of his car's in the 70's. This was not a new concept however and has been used in flight applications since the early 1900's in order to make a wing create more lift to the deficit of more drag (Wickerbill).

The Gurney is quite a blunt method of producing lift/downforce but can also help to rectify deficiencies in the wings design. It helps to trim the angle of attack of a wing thus allowing a higher angle of attack before separation occurs. In terms of flight, had a designer miscalculated the design profile of his wing adding a gurney may help to rectify the flight pattern, as such the same can be done with an F1 wing. The advantage of this in terms of motorsport is that you can continue to leverage more downforce from a wing by increasing the wings angle of attack, however by default this will create a larger proportion of drag. This is caused by the airflow on the rear of the wing being unable to sustain the same AoA and so separation occurs as the boundary layer increases at the trailing edge.

Gurney flaps are not only utilised on the Rear Wing in F1 but also feature on the Front Wing, Beam Wing and more recently the teams have started using them above the Diffuser.

As we can see in the image above the teams are using Gurney Trims above the diffuser that are either fully detached from the Diffuser and angled like a Winglet to increase their effectiveness or as we can see in the case of Mercedes (below) some teams continue to have a blunt section of Gurney at the outer extremities with a perforation along the central section