Doble Drs De Redbull F1 2012

Analysis: Red Bull DDRS
Posted on October 15, 2012

It’s rare a technical development passes without anyone noticing and of all teams its surprising Red Bull pulled off that trick in the past few races. As they were seen to have a Mercedes-like Double DRS (DDRS) system in use in Japan. It transpires the system was track tested in practice at Monza and raced in Singapore. Part of the secret ofthe Red Bull DDRS is that the system is wholly contained within the rear wing. Only the plate over the end of the rear wing flap gave away the systems existence. With this system Red Bull are able to shed even more drag when DRS is open, thus giving them a top speed advantage in qualifying and when DRS can be used in the race.

Layout

Oversize plates (yellow) on the flap move when DRS isopened, but keep the duct covered when DRS is closed.

Red Bulls adoption of DDRS is also surprising; as it’s the first time a team have exploited this technology since Mercedes introduced it for the start of 2012. This might be in part due to the system being banned for 2013 and teams are looking at the passive Drag Reduction Device (DRD) as tested by Lotus\Mercedes. As already mentioned the RedBull DDRS stalls the rear wing and not the front wing, as with Mercedes solution. Thus the system is self-contained within relatively conventional rear wing elements. We can clearly see the oversized plate that seals the duct when the rear wing flap is in the closed position. When DRS is activated the flap swings open and the duct is revealed. The high pressure that builds up above the rear wingmain plane, invites flow to pass through the duct and this flow can be used to stall other parts of the rear wing. From the shots of the system with the DRS open in Korea it’s clear to see the duct routes vertically down, passing inside the double skinned endplate.

When DRS is opened the duct is uncovered to blow a slot lower down on the wing

What surfaces are being stalled?
Middle of thewing
Quite where this duct exits to stall the wing is not clear. Most reports suggest is stalls the centre of the beam wing or the centre of the diffuser. This is entirely possible, the Mercedes system routes through the endplate and then into the beam wing. If this is the case for Red Bull then the duct would either exit through a slot in the middle 15cm beam wing or ducting further down to thediffuser. Blowing a slot in the area will stall the airflow and this would lead to the reduction in downforce. The middle 15cm of beam wing is allowed to have a slot, as this area is exempt from the closed section and minimum radius rules, introduced to ban F-duct style stalling slots in 2010. However these central areas of the beam wing and diffuser are quite efficient, as they do not induce a lotof drag from tip vortices. Stalling the flow in the middle of the wing would have a knock on effect in stalling the general flow behind the car, but I don’t believe this would be an effective use of the stalling on the back of the car. It would be better to stall areas which do induce a lot of vortices and therefore drag. These areas tend to be at the wing tips, so the obvious areas to stall aretop rear wing tips, the beam wing tips and the outer corners of the diffuser.

Wing tips
Both of these wing elements are allowed to have slots in the outer 5cm or in the endplate itself, while the diffuser is not allowed to have slots in this area. So the focus moves to stalling the wing tips. As the top rear wing is already rendered ineffective by DRS being open, the flap being open leaves therelatively flat main plane unloaded, so little drag will be induced at its tips. Looking at the Red bull wing at the past few races show only one sign of holes under the top rear wing, but these were only seen in one practice run in Japan and have not been seen again. Its possible Red Bull evaluated blowing this area and discounted it.

It’s also possible that a system could blow both the...