The Evolution of the Modern Front Wing – Part 3

Before I begin the third part of this series, for those of you who are new to this site, I would advise visiting parts 1 (https://thewptformula.wordpress.com/2013/02/27/the-evolution-of-the-modern-front-wing-part-1/) and 2 (https://thewptformula.wordpress.com/2013/04/02/the-evolution-of-the-modern-front-wing-part-2/) as identifying common themes and characteristics will be a lot easier!

Year three of the current regulations saw the progression of ideas that were introduced in 2010, as teams finally got to full grips with which concepts were working best for the current aerodynamic rules and also how these airflows interact with the tyres.

The tyres are a big factor in car dynamics – Pirelli even supply wind tunnel tyres, that are much smaller, that are designed to replicate the tyre used on the full car during the season. This is because the structure of the tyre allows for deformation under loading. This can happen during a corner as well as over bumps and kerbs.

This deformation angles the car slightly differently (pitch, forward-to-back movement; or yaw, side-to-side movement; warp, a combination of the two) during acceleration, braking and cornering, which affects the path that the air takes travelling along the car as well as the mechanical grip available to the driver in each of these phases.

The front wing is therefore a crucial component when controlling the outcome of how the car behaves during these phases as it manages the flow from the very front to the very back of the car.

This is why we sometimes see cars that perform better in the wet, as the treadblocks of the intermediate and extreme wet tyre raise the car by more than a centimetre, changing the characteristics of the car’s aerodynamics as a result.

Common Themes

Red Bull RB7 FW

The height of the nose continued to gain altitude during the season as emphasis on forcing incoming air underneath the front of the floor became apparent for most of the teams. This effect forces the diffuser, probably the highest downforce producing device on the car, to work harder and therefore extract a higher volume of flow, pushing the car downwards and only increasing its effects as a result.

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The cascades and endplates also saw an attention to detail as the designers fettled with controlling tyre wake (turbulence caused by the rotation of the tyre and oncoming airflow at speed) and extracting further downforce from other components downstream of the front wing. Lotus were a particular team that trialled many endplate configurations at different circuits to optimise this area.

McLaren’s philosophy

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It is at this point, the beginning of 2011, in the current regulations where McLaren chose to stick with a more traditional front wing design – a main plane (silver in the above image) and two flaps (both red) are the primary downforce producing components. Other teams chose to go down a more adventurous route that I will explain later on in this post.

These leaves a total of three elements, all of them with a large surface area. The reason behind this concept is to induce as much front downforce as possible, as each element is very large. Reducing the amount of elements reduces the volume of laminar (consistent, straight) flow however, making management of the airflow a harder job.

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To achieve good management around the front of the car, McLaren introduced the ‘r’ shaped cascade winglets that lie inboard of the main cascade winglet. They are mounted to the wing by the base of the ‘r’ and also by a vertical strut to reduce the amount of flex at the tip.

Its role is divided into two parts: the vertical part of the cascade is used to separate and guide flow over its desired part of the wing, directing flow specifically to one area and therefore around a different region of the front tyre or front suspension. The horizontal section is designed to produce a vortex at its tip, taking airflow to a desired area, consistently, at almost all speeds that the car is moving at.

The ‘r’ cascade is split into two elements, which aids the vortex generation at the tip. The second element (furthest back) also has a slight lip that helps to splay the flow outwards.

McLaren spent time developing their endplates, often changing the number of slots that allow high pressure flow on the outside back inside to the channels in the wing, energizing and controlling the flow coming off of the wing and around the outside of the front tyre. These changes do help the main elements of the wing produce downforce, but they are primarily for flow management purposes.

The ‘other’ philosophy…

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Red Bull pioneered a concept that involves a gradual progression of the gradient of the wing across numerous elements, starting with just three elements in 2009. This soon became four, and the image above shows their 2011 front wing, consisting also of four tiers.

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This philosophy also involves the attachment of each of the elements to the footplate (the base of the endplate) creating a slotted profile across the entire wing. This is evident in the image above. The gap in the endplate reveals where the each element swoops vertically downwards dramatically right at the outboard edge of the wing, meeting the curved carbon base below. McLaren do not follow this trend, as their elements attach directly to the endplate horizontally.

The advantage of this method is that the greater the amount of slots, the more consistent flow travels between the elements, resulting in a cleaner, more laminar final resultant airflow coming off of the front wing and around the front tyre. This is more manageable airflow than that trailing off of the McLaren front wing and can therefore be directed more effectively downstream.

The drawback of this technique is that it actually produces slightly less downforce than a wing that has less elements and a higher surface area. However, in Red Bull’s case, clearly they have enough downforce at the front of the car to be able to extract the best from this concept! This therefore means they can further concentrate optimizing the rear of the car, creating a perfect balance for their drivers.

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Williams were one of the first teams to latch on to this idea. They had an arguably one of the most sophisticated designs on the grid during 2011 pre-season testing.

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They were also another team, along with Lotus, exploring the possibilities of the inner flap section as seen above. The inboard edge of the two flaps have differing profiles, the older one being slightly crinkled, the newer with a sharper, straighter edge. This straight edge inboard flap area continued to develop throughout the season and has since carried into 2012 and 2013.

The idea behind this straighter edge is similar to the idea behind the McLaren ‘r’ cascades. At the very tip of the top flap edge, a small space is exposed beneath it. Accompanied with the sharp profile, air coming over this section will divide quickly above and below the top flap. When it meets the other side, much higher pressure above the flap meets the faster lower pressure beneath it, creating a vortex. This is, like the McLaren solution, a great way of directed flow to desired components downstream of the car.

Endplates

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Likewise with the main concept of the front wing design, there also seemed to be an alternative route for endplates. Noticeably, Red Bull have a very simplistic one-piece endplate that simply meets the surface area requirements in that region as they rely mainly on the very outer tips of the wing elements to manage airflow around the front tyre.

However, examples such as the Lotus endplate above are much more complex as they feature a multitude of guide vanes and flick-ups to turn the airflow outwards and around the tyre. These designs also integrate the main cascade winglets much more than the simplistic ‘Bull concept, the image above showing a beam attaching from the (black) winglet to one of the (red) guide vanes.

Ferrari derived a solution combining the pair of these two ideas. Their wing featured a single wall endplate that ran right across the length of the wing but also included a guide vane sat in front of it. This vane is allowing air to take an alternative pathway and leads to a different component downstream of the car than the path that the single wall endplate flow takes as the two are angled slightly differently.

Note how the guide vane has a much more aggressive angle at its base than it does at all other points along the trailing edge. This suggests that the air is flicked around the tyre at a greater angle at the lower part of the vane and could possibly be diverging its path to beneath the floor. This is in contrast to the less angled part above, with this airflow possibly interacting with flow coming around the sidepods further back.

Under-nose turning vanes

You can also see in the above image the large turning vanes beneath the front wing nosecone. These manage air coming in directly beneath the nose tip and dissipate it much more evenly to a designated area of the car. This process allows other components to work more efficiently due to the more laminar flow acting upon them. Large volumes of turbulent flow will not allow other aerodynamic parts to work well as they can stall them. This then produces drag and lift, slowing the car down.

We can also see this here on the underside of the Williams FW33 (image by Giorgio Piola). They are attached right at the back of the nose cone, with the extensions reaching back beneath the chassis.

The birth of these turning vanes occurred during the back-end of 2010 and started featuring on many of the cars during 2011. This turned out to be another big avenue of investment for teams as the area beneath the nose is free of a lot of restrictions.

It is during the 2012 season that most of the development in this region occurs, which will be a main feature in part four of this series.

Flexible Wings

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All aerodynamic devices have an element of flexibility when loading takes place. If they did not flex then the structure would break.

By regulation, however, teams must not breach a certain limit of flexibility on most aerodynamic components as this is deemed illegal. This is because a lot of flexibility of some devices, such as winglets and wing elements, can change the characteristics of the car dramatically between high-speed and low-speed (where little loading occurs).

In 2006, Ferrari’s rear wing had two elements like today’s generation: a main plane and an upper flap. Under extreme loading at high-speed, the gap between the two elements closed up, creating one single profile as a result. A single element rear wing would stall at its underside as the flow would detach itself as the angle of the wing increases towards the trailing edge.

Adding a second element allows a greater angle of attack on the wing without stalling the air beneath it, creating more downforce as a result.

When the elements close together on the Ferrari rear wing, the wing stalled and reduced drag and in turn allowed the car to reach a higher top speed. When they FIA realised this was occurring, they saw it as an unfair advantage and made it compulsory for the rear wing to not exceed a certain amount of flexing during high loading.

Back to front wings…

Do we all remember Hungary 2011? That is where things really kicked off regarding Red Bull’s ridiculously flexible front wing.

The front wings also under-go load testing, with large weights attached to the endplate of both sides of the wing. They must not exceed 10mm of flexing (2013 regulations) under 1000N of loading.

In the image above we can clearly see that the RB7 front wing is almost touching the ground as it approaches high velocity. The sub-image on the right shows the car stationary in the pitlane.

This flexing induces a small amount of “ground-effect”, when a low pressure zone is created between the ground and the bottom of the aerodynamic device (in this case, the front wing endplate). This low pressure is what produces extra downforce as elements of the car are closer to the ground. If you want to read more about ground effect for cars, follow the link here – http://en.wikipedia.org/wiki/Ground_effect_(cars).

While Red Bull were pushing the entire endplate section downwards, McLaren came up with an innovative concept using their front wing mounts.

In the image above, there are clear gaps between the lower part of the front wing pillars and where the pillars are attached to the wing mounts. This occurs also under extensive loading and rotates the entire wing backwards, forcing only the very back of the endplate to reach near-ground level.

This is much easier to design as the Red Bull solution involves a complex arrangement of carbon composites to achieve the whole profile to flex downwards. McLaren’s solution, I am told, also helps to reduce drag when the endplates reach a certain angle, as beyond a certain point the low pressure area stalls.

Sorry for not being able to put this up yesterday, technical issues! I am probably incorrect about some of the theory as I have forgotten a bit of it (it WAS two years ago…). Thanks for reading and I would definitely appreciate any feedback.

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5 thoughts on “The Evolution of the Modern Front Wing – Part 3

  1. Morris Dancer

    Ground effect always makes me think of ekranoplans.

    Anyway, that was an interesting read. What do you think of the idea of reducing the size (and possibly simplifying the potential for development) of the front wing? It’d help to stop them being lost so often (they’re very wide now relatively to the size of the car) and cut the overall level of downforce.

    Reply
    1. thewptformula Post author

      They use ground effect to keep them up, which is all to do with the shape of the underside of the wings and fuselage etc.

      For next year? I think it will create a new challenge for teams. Decisions such as whether to direct airflow inside or outside of the front tyre and then how to utilise the space remaining on the wing surface will be interesting to study over the next few seasons.

      As for them getting knocked off I totally agree, it must be very difficult to judge where the endplate is, even if they know where their wheels are (with the exception of Perez).

      Not sure entirely what the new regulations are but they will have slightly reduced downforce, certainly to begin with.

      Reply
  2. Pingback: The Evolution of the Modern Front Wing – Part 4 | theWPTformula

  3. Romaine

    My spouse and I absolutely love your blog and find nearly all of your post’s to be precisely what I’m looking for.

    Do you offer guest writers to write content for yourself?

    I wouldn’t mind creating a post or elaborating on many of the subjects you write concerning here.

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    Reply
    1. thewptformula Post author

      Thanks! Unfortunately I’m not open to guest writers as this blog is a representation of my work. I might have a future project in store though so we shall see…

      Reply

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