How the F1 rules changes for 2009 are meant to improve racing (part 2/3)

Posted on | Author John Beamer

The high rear wing on 2009 F1 cars is designed to improve racing
The high rear wing on 2009 F1 cars is designed to improve racing

Guest writer John Beamer continues his look at how the F1 rules have been changed for 2009 in a bid to encourage closer racing and more overtaking.

Rear wing

Changes: Like the front wing, the rear wing will look substantially different ?ǣ superficially it will be narrower and higher. The top of the wing is raised by 150mm to 950mm and is now level with the summit of the engine cover. It is also narrower, reduced in width by 250mm to 750mm.

Allowable depth for the upper section has increased from 200mm to 220mm, to permit slightly more cambered and powerful aerofoils. As in 2008 only two elements are allowed. In addition the minimum area for the rear wing endplates has increased from 230,000mm2 to 330,000mm2, although part of this extra area allows for the taller device.

The beam wing remains in the same position (300mm above the reference plane) but, like the upper element, its maximum depth has increased from 75mm to 100mm. Again, as in 2008, the beam wing can only contain a single section.

Performance implications: By raising the height of the wing it will run in cleaner air and be more efficient. More downforce is available for a given angle of attack which, all else being equal, makes the associated wake smaller. However, the reduced plan area cuts total downforce and teams may simply reclaim lost grip by running more cambered profiles.

Specifying larger end plates gives teams an opportunity to better manage wingtip vortices, which will help contain the wake and reduce drag. Moreover, the narrower wing should reduce the size of the vortices induced by the rear wing section.

The other consequence of raising the wing is to decouple it from the diffuser ?ǣ moving the diffuser back helps too (more on that later). How does raising the wing help? The 2008 regulations cause the rear wing to generate a low pressure zone at the base of the car, thereby creating a shallower pressure gradient for the diffuser to work against. In theory, raising the wing pushes this low pressure zone higher so upwash from the rear wing/diffuser combination is muted.

The high rear wing on Ferrari's F60
The high rear wing on Ferrari's F60

Marks 6/10: The concept of making the rear wing less sensitive is sound although the implementation is questionable. Despite the width reduction and height increase, by allowing teams to run more cambered profiles, the wake pattern is likely to remain similar.

Decoupling the diffuser from the rear wing is superficially good as it helps reduce upwash from the rear of the car but in practice the pumping effect has less influence on the wake than the steepness of the aerofoil or diffuser does. In all probability upwash will only be slightly reduced, if at all.

The narrower and higher wing will also look different. Many fans complain that the changes may make the cars look less racy. Is this a problem? Perhaps to some ?ǣ but show a 1960s aficionado Michael Schumacher?s legendary F2004 and he?d say much the same.

Barge boards

No barge boards on the McLaren MP4-24
No barge boards on the McLaren MP4-24

Changes: The rules governing the positioning of barge boards are some of the most complex in the new regulations and bring about a significant change to the look of a 2009 car.

A large restricted zone is defined which hugs the monocoque, extends the width of the car and spans from 625mm forward of the rear edge of the cockpit entry template to the front wheels ?ǣ no body work is allowed in this area. A similar zone is defined in the 2008 regulations but is smaller, geometrically simpler and permits the plethora of forward turning vanes, barge boards and vortex generators that adorned last year?s cars..

Additionally, in 2009 a second zone is specified that extends from 450mm to 875mm forward of the rear edge of the cockpit entry template and overlaps with the zone defined above. No closed sections are allowed in this second zone.

In practice bodywork in the second zone must integrate with the sidepods or else the closed section requirement is violated. Simple fins, vanes and axe heads are permissible provided they comply with the closed section limitation.

Performance implications: Barge boards perform two roles: first, to manage air around the side of the car and second, to improve the efficiency of the floor. They work using vortex generators and panelling to appropriately direct and channel air flow.

Under the 2009 regulations barge boards as we know them are more or less banned. This has profound implications. First, it will be harder to feed the floor by appropriately directing vortices generated from the lower edge of the bargeboard. Second, it will be harder to shape air around the sidepod undercut through the coke bottle zone to the diffuser. Not only will under floor downforce fall but pressure above the diffuser will be higher, which further reduces the ability to generate under body downforce.

Marks 8/10: The FIA has done a thorough job making sure that the changes support both of its original objectives. Barge boards create a lot of turbulence that extends beyond the car?s form factor, so restricting the boards? shape and ability to generate vortices will help reduce a car?s wake profile. As a consequence the entire aerodynamic package in this region is less sensitive to turbulence, which promotes closer racing. Sure, downforce suffers but the benefits are worth it.

At the same time there is still scope for aerodynamicists to apply some design latitude so we could see different and innovative solutions, especially given the convoluted writing of the regulations. Expect aerodynamicists to pay a lot of attention to what rival teams are doing with barge boards and to copy the best ideas.

This series continues tomorrow with a look at the rear wing and barge boards. This is a guest article by John Beamer. If you want to write a guest article for F1 Fanatic you can find all the information you need here.

How the F1 rules changes for 2009 are meant to improve racing

More on the 2009 F1 rules

Images copyright: Toyota F1 World (1), Ferrari spa (2), (3)