McLaren MP4-27 - exhaust positioning 14 March 2012
With the FIA placing tight restrictions on exhaust-exit positioning for 2012 in a bid to eliminate blown diffusers, teams' solutions in this area and how those solutions influence their cars' aerodynamic set-ups is already a real talking point of the new Formula One season. McLaren's engineers have opted to send the hot exhaust air in a wide and low direction towards the rear of the car (yellow arrows), between the rear tyre and the diffuser. This utilises a scientific concept called the Coanda effect, which helps divert the airflow downwards and along, even though the exhaust exit is angled upwards (left-hand red arrow) as required by the regulations. The hot air is guided by an assortment of curved surfaces which surround the exhaust (see the other red arrows). As the surfaces curve away from the flow of air, low pressure builds, which in turn forces the air to remain attached to those surfaces. The Coanda effect has also been exploited by Sauber and Ferrari this year.