Williams’ low-downforce concave rear wing

F1 technology

Posted on

| Written by

Before the 2009 regulations revised the rules on F1 aerodynamics there were only four Grands Prix on the calendar for which teams built radically different car configurations: Montreal, Monza, Monaco and (sometimes) Spa.

Since the rules change, teams’ rear wing development has been much more restricted by the FIA. Given the need for the front wing to balance rear downforce, many teams opt against bringing a new low-downforce configuration??for the Canadian race.

However, unlike in other races the low downforce nature of the Giles Villeneuve track does give some leeway to designers to tweak rear wing design.

Last year Renault debuted its ‘M’ wing – so-called because of its shape. This year the most obvious visual rear wing change was a concave design from Williams.

The first illustration shows Williams’ rear wing from the start of the year. Apart from the colour it’s little different from that of any other car in the pit lane.

The regulations require a two-element device and the only design considerations are the profile of the endplate (which don’t diverge significantly) and the chord length of the two elements, which dictates the effectiveness of the DRS.

The shorter the cord length of the flap the more effective the DRS system is at shedding drag when opened as the gap between the two elements in maximised. This trade-off comes at the expense of total downforce when the rear wing is closed.

The second illustration shows Williams’ concave rear wing developed for Montreal. Any deviation from a straight edge is going to reduce downforce simply because the area that the air can work with is less that it would be otherwise.

For the concave wing, the angle of attack of the wing is steeper towards the endplates, which means that less downforce is produced in the centre.

Therefore the total downforce produced by the rear wing is lower than the old configuration. Less downforce equals less drag and a higher-top speed.

Why this particular shape as opposed to say an ‘M’ profile? The engine cover alters the profile of the air flowing to the rear wing so by optimising the shape the rear wing elements designers can increase the efficiency of the device (as measured by the lift to drag ratio.

The objective is to ensure that the airflow is perpendicular to the wing on contact – this allows to airflow to work the wing while giving up the least amount of drag.

In the coming races expect Williams to return to its more traditional wing – the Montreal edition will probably return in a few months’ time for Spa.

F1 technology

Browse all F1 technology articles

Illustrations ?? John Beamer for F1 Fanatic. Image Williams/LAT

21 comments on “Williams’ low-downforce concave rear wing”

  1. And all of this is useless without a driver who can’t make good on it.

    1. no, even the useless driver can gain an advantage, his lap time will be a little bit less useless.

      1. LOL. Common sense at it’s best!

        1. ouch lol

      2. Ouch, thats harsh.
        Maldanodo, isnt THAT bad, he won a race this year.
        Even Senna is THE worst either. I think we can leave that title for several other drivers. Ill not name names here as I dont have energy for a flame-war.

        Im actually happy for the good form Williams has shown this year. Good to see them back in the mix and trying new ideas, even if they dont work.

        1. Just because you can’t bear to name Alonso as the worst…come on – be brave! ;)

        2. Maldonado and Senna have had their true flashes of pace, unlike – as you say – some other drivers.

          I won’t propose names either, but probably to some of us one particular driver springs to mind. All i can say is that his name begins with K and ends with arthikeyan.

          As for what PM has said, there is some truth to that. If a rubbish driver acquires new device and can’t set it up properly, it may as well disrupt the peaky balance of an F1 car, therefore making his laptimes even more useless and inconsistent.

          Look at JB and his problems with his car’s balance, i can only suspect that down there these kinds of problems are even worse.

  2. As mentioned in the article, an advantage of this concave wing is that the engine cover messes up the air flow in the centre of the wing. An advantage of reversing the bow (so more surface area at the centre like Williams’ rear wing at Spa last year) is that less intense vortices are created at the wing tip edges. I’m not an aerodynamics expert, but to me it seems odd that the advantage of the cleaner air outweighs the extra vortices created by the wing tips.
    Another possible advantage of this config is that the air that flows through the hole between rear wing and beam wing is less obstructed.

    1. Another possible advantage of this config is that the air that flows through the hole between rear wing and beam wing is less obstructed.

      While the work on that article is really nice, the illustrations and explanations, it could have been better if we had a CFD simulated flow to further backup or reject that theory. Sadly, the easiest way to do that costs about $2,000 and takes some 22 hours for decent simulation, without mesh creation. Note: I’m aware about OpenFOAM, it’s just I don’t have both the time and my old Linux cluster anymore.

      What’s most intriguing is why the wing hasn’t worked particularly good.
      My answer to that would be the above-mentioned engine cover, which hasn’t changed visibly (IMHO, I may be wrong, I follow other teams more closely) and in the top speed department Maldonado and Senna have both qualified at the end of the chart.

      I’m sure that Williams have done their homework, still, I’d love to understand what has gone wrong. I’m not fully discarding the tire situation and messed up setup, while also considering the wing profile as pure experiment and data harvesting run.

      Kiril Varbanov,

      1. dysthanasiac (@)
        18th June 2012, 17:09

        It’s possible that the increased height of the center section relative to the diffuser diminishes the effect of the diffuser’s upwash on air flow under the wing. Most teams have adopted so-called “monkey seats” not only to help extract air from the diffuser, but also to help keep air flow under the rear wing attached, which is where downforce is born, so to speak.

        Of course, this configuration might have been implemented to actually stall the rear wing at speed. I think that’s plausible due to the nature of the turbulent flow from the engine cover interacting with what became the weakest part of the wing.

        1. Just ran into that article again, while looking for some 2012 rear wing incarnations.

          First, a cosmetic correction to John Beamer, the author – the M-shaped rear wing was introduced by Renault in 2010, not last year (2011). More on the wing itself:

          I would suppose that prime reason for such design would be that the center section of the wing will retain lower pressure, and such effect would cause subsequent lower pressure levels at the wing tips, meaning less vortex as well.

          Generally, the wing tip vortex will have low pressure core, but their overall strength is resultant of pressure differential between upper and lower wing surface, so reducing it in one side of the equation would mean less wing tip vortex, too.

          That’s my humble aero guess, we haven’t seen whether this had the desired effect, but the wing was raced anyway.

  3. How do i get notifications for follow up comment?.Someone should help out

    1. You should get notifications only when someone mentions your user name like this @ribf1 so you should be getting this now.

      Next to that, you can tick the “notify me on follow up comments via e-mail” box below the commentary window and that should get you all new comments with the given article

      1. Next to that, you can tick the “notify me on follow up comments via e-mail” box below the commentary window and that should get you all new comments with the given article

        Which in effect is just a massive email bomb of notifications lol. So don’t tick that box.

  4. yes, i have a name. what of it?
    18th June 2012, 23:17

    they should get rid of their 2 drivers and replace them with onces who can take corners correctly. maybe Kubiza if Ferrari/Sauber don’t snap him up??? or maybe Mansell? he never officially retired did he? :D

    1. Mansell? Great idea! Maybe Ferrari should hire John Surtees, and McLaren John Watson. Not to mention that Lotus could bring Jackie Stewart back! We could have an entire field full of ex-drivers!

      In all seriousness, though, there was actually a series where old-timers raced each other (the likes of Mansell, Jones, Fittipaldi…). It collapsed pretty quickly, and some of the drivers were too fat and old to do anything.

  5. Reminds me of the 1994 Benneton

    1. Because that one had a fully straight rear wing? Or do you mean the lower element that they copied from Williams? But yeah Williams had that curved element too in 94.

      Ferrari had a Monza spec curved rear wing in 2009.

  6. What is far more interesting to me is that they’ve completely gone 180 from their low-downforce configuration of 2011, which was lighter towards the endplates and steeper towards the middle.

Comments are closed.