I just saw a very interesting video clip in YouTube, which explains the functionality of the aerodynamic W-duct, more commonly known as a “front F-duct”. This system was allegedly run by Mercedes GP in some of the final races of the 2011, with the drivers reportedly unhappy about the effect it had on the handling on the car. This is the clip:
What the author of this clip is suggesting is that the duct has two different functions. In straights, it channels the air through a central tunnel of an “air valve” towards the main components of the front wing in order to stall them (i.e. minimize drag and downforce). Then, in corners, the air is re-directed via the air-valve to the part of the front wing that is at the inside (i.e. in left-hand corners, it channels the air to the left part of the front wing). However, the reason for doing this is exactly the opposite. The air passes under the wing elements creating additional downforce and, at the same time, it brings the whole left part of the wing closer to the ground (it therefore negates the roll effect to the wing).
It’s a very interesting idea. The author argues that the air is directed via the central channel between -1 / +1 degrees of turning, whereas it is directed via either the left or the right channel when the degrees vary from between 1 to 6. Such a system is completely passive and it doesn’t involve driver’s input, nor does it incorporate moving parts. Having said that, it’s clear to see why such a system would be very sensitive inside a corner, where the rate of turning is never steady and consistent. A sudden correction of a slide, for example, would cause the airflow to switch to either the central channel or the exact opposite, meaning a completely different aero balance at the front. It would also be a challenge for the aerodynamicists to ensure that the airflow detached and reattaches smoothly and quickly.
It is rumoured that Mercedes haven’t binned their front F-duct program, and that they will be running a revised version of it during the Barcelona pre-season tests (starting tomorrow). It will be interesting to hear the drivers’ comments and, more importantly, get some info from the journalists on track on how the cars seem to behave, visually. To anyone how hasn’t read it, I strongly recommend subscribing to Autosport Plus and reading Jerome d’ Ambrosio’s track-side impressions from Jerez testing…