Update on how it links to the front wing

Original article/

I’ve heard a lot of reporting about the Mercedes F-Duct stalling the rear wing and the likelihood of other teams already having a similar system.

I can see the logic in why people think that the DRS controlled duct blows the rear wing elements in a bid to reduce drag. I haven’t seen any evidence of this being the case; equally I can see several issues with this theory. The problem with the theories on the DRS duct stalling the rear wing are twofold; firstly the DRS is already cutting immensely, secondly the rules greatly restrict the ability to stall the rear wing. Back in to 2010 teams were using blown slots across the full width of the rear wing, these being used with perpendicular blowing to stall the wing or tangential blowing to act as an additional slot gap for more downforce. The rules introduced in 2011 aimed to prevent both of these types of slot.

To stall either the top rear wing or the beam (lower) rear wing, you need to blow a slot. In the post 2010 rules, slots are banned in any section of the rear wing (via a 100mm minimum radius rule); this ban applies to all three wing elements aside from the middle 15cm. So to use the DRS duct to blow a rear wing slot, all you’ll stall is the very centre section of wing. This area creates very little induced drag (most of that’s created at the wing tips), so stalling it will not improve top speed by much. Thus it will provide very little benefit.

It’s possible the DRS Duct could stall the flow around the sidepod, exhaust or diffuser. I’ve got no information on this, or a valid reason how this would benefit the aero. In my opinion the blowing to stall the front wing is still the most valid theory. Pictures have merged today of Schumachers car lifted on a crane that shows the slot sunder the front wing. other pictures also show close ups of the rear of the car, do not show any slots in the top or beam wings.

Search on sutton images for pictures d12aus3468.jpg, d12aus3467.jpg, d12aus3465.jpg

I suspect the two ducts leading from the beam wing into the engine cover are part of the system. Either taking the DRS-duct flow to the front wing directly, or by using the DRS-duct to switch the F-Duct. I can;t find where the F-duct switch is sited, perhaps inside the rear wing, in which case the two beam wing ducts might be of different uses, one feeding high pressure airflow to the F-Duct and the other feeding the flow to the front wing. As this is an evolving theory, I’ll post more on this system as we start to understand it better.

I’ve looked at the McLaren, Red Bull and Ferrari rear wings, as yet I can see no shaping to suggest a DRS-Duct is packaged inside the endplates. There’s little doubt these teams must be working on similar solutions. Although Red Bull and Lotus may probably not be developing this solution, as they are now querying the FIA on its legality LINK

We have now acceptance by the FIA that the DRS duct is legal, that Mercedes are running this system and pictures show the duct emerging from the beam wing reaching forwards inside the engine cover. Presumably, to reach towards the front-end of the car. No doubt more information will soon emerge on these systems.

other links:

DRS open showing the duct open beneath the flap (via AMus)

LINK

Rear wing no sign of any slots in the middle 15cm

LINK