The Evolution of the Modern Front Wing – Part 4

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For the final part of this series, we shall be looking at the development of the front from 2012 through to where we are currently in 2013. If you are new to this series then I advise looking at the previous articles I have written to understand the path that the modern front wing has taken to reach the point where we are now.

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The 2012 Formula One season saw the refining of the modern front wing, with most teams firmly set on a design that simply needed fine tuning across the season. This meant that we mainly saw the development of the cascade winglets and how the planes of the wing met with the endplate/footplate at the outer edge of the wing. This slowing in development was due to the understanding of the Pirelli tyres and how to create the best flow structures around them. As mentioned in my previous articles, the tyres have a large impact on how the airflow travels around the car and they have a great influence on the components downstream of them.

Wing Elements

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Increasing the number of elements at the outer region of the wing became a common trend as more slots in the wing allowed for a steeper, progressive gradient along the profile, which in turn also provides more consistent airflow. The consistency of the flow produces less peaky downforce rather than better overall downforce.

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The current McLaren wing philosophy is potentially a greater downforce producer than, say, the Lotus wing but may only operate well in a certain window of flow speed. This is because it consists of fewer elements and a less progressive gradient, therefore it probably works best at higher flow speeds as there is less risk of airflow detachment as flow moves across the wing profile at a higher velocity.

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At the United States GP in Texas, McLaren introduced a revised layout that featured a design much more in line with what the majority of the grid already had, with each element of the wing swooping downwards sharply to meet the footplate. The green lines show each of the three elements and the yellow underline shows the footplate area. In comparison to other wings, three elements is still quite a low count compared to Ferrari’s six (introduced in late 2012 and still in use for 2013). They have kept this number of elements because the McLaren MP4-27 aerodynamics work differently compared to the Ferrari F2012 in terms of tyre interaction as well as how it produces its downforce. Adding elements to the wing to create more consistent downforce/general flow is not necessarily a given as each car is totally unique.

Noses: Stepped vs Non-Stepped

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The biggest change to front wings for the 2012 season was arguably the nose height. The nose height predicts the split of airflow over and under the car. Driving more flow beneath the car works the T-Tray area harder, forcing more air underneath the floor which produces a low pressure region which therefore, in combination with the diffuser, creates more downforce. This is why engineers and designers prefer a higher nose as a greater volume of air can travel beneath the chassis and underneath the floor.

The FIA revised the regulations stating that the nose must not exceed 550mm above the reference plane (the lowest point on the car – it is not a defined point as each car has a slightly different lowest point due to the rake and ride height it is set at). This change came about because the governing body feared that the noses were getting too high and, in an accident, could penetrate above the cockpit sides and injure a driver.

However, the regulations also read that the chassis must have a maximum height of 625mm above the reference plane until just in front of the front wheel axle line. There is then a 150mm horizontal section where the transition between the two heights must take place, hence a prominent step is evident.

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McLaren started the 2012 season with a low slung nose, as did Marussia. Many analysts criticised this but the design did not come about out of choice. Both teams designed their cars around a lower chassis height which had been incorporated on their previous models since the rules changed in 2009. Raising the chassis to maximise the new height rules would mean changing the front suspension mounting points, which changes the mechanical balance of the car, as well as changing the aerostructures of the car around the front wing and chassis. It was therefore easier for both teams to design the car with a lower front end.

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Unlike Marussia, who stuck with their low nose throughout the whole season, McLaren decided to try to replicate the higher chassis height by simply raising the nose to the maximum level possible within the limits of their chassis design. It does not quite meet the maximum 550mm limit but it was the best the team could do given the design of the ’27. This allowed more airflow beneath the chassis to reach the full potential of the floor.

One of the problems with the stepped nose was airflow detachment along the top surface of the car. Because the chassis height is fixed from just in front of the front wheel axle line to the cockpit entrance, the top of the car is completely flat when a stepped nose is in place. This leads to the flow detaching from the chassis top and spilling over the sides, disrupting other aero paths that are heading around the sides of the chassis. The step itself also causes drag due to high pressure build up along at the stepped area which also led to problems with flow management to the rear wing, as the flow spread outwards and upwards instead of travelling straight back.

Red Bull and Sauber came up with some solutions to this issue.

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A slot was introduced in the RB8’s step, fed by the raised chassis “ears” that pronounce themselves from the rest of the body. This slot had two purposes: the main purpose was to reduce the build up of high pressure at the step zone to reduce drag. This was done by diverting the air hitting the step through the slot, leaving less air to travel over the chassis stop. This also reduced spillage over the chassis sides. The secondary purpose of the slot was to channel the excess air from the slot to the cockpit area by the driver’s feet, which cools the driver. Teams often leave an opening on the nose of the car to do the same thing, but Red Bull found a nice way of integrating this.

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Sauber produced a neat duct system that ran from a forward opening at the base of the chassis to a reward facing slot along the top. The base slot collected boundary layer flow beneath the car before feeding it up an ‘S’ shaped duct to the slot above. This flow was then projected backwards along the top of the chassis. This introduction of high energy airflow reduced the amount of spillage over the top part of the car as the flow tended to remain attached for longer.

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Red Bull’s 2013 challenger, the RB9, has an almost identical copy to that of the Sauber C31 from last year. The image above shows the internal duct-work that is housed within the nosecone, with the slot evident at the top of the nose. Red Bull remained one of the few teams to retain a stepped nose layout for 2013, although it received some vanity panel treatment to reduce high pressure build up along the step.

Turning Vanes

2012 saw the main transition from under-nose turning vanes to under-chassis turning vanes, the difference between them being that the former is attached to the underside of the nose, the latter attached to the underside of the chassis just after the nose.

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The F2012 was launched with under-nose turning vanes that branched down and outwards, diverting airflow efficiently towards the sidepod leading edge and the T-Tray.

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These were then upgraded to vanes mounted onto the chassis. These vanes were split into two, each element having an individual profile in the shape of an aerofoil. They are joined to eachother by a small join piece to prevent flexing at high speed, ensuring that the airflow is guided to the necessary destination at all speeds. By the end of the season, almost every team had under-chassis turning vanes as there is greater freedom to produce ideal aerofoil shapes in this area than beneath the wing.

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However, McLaren still maintain the under-nose vanes to this day. Their MP4-28 has underlying aerodynamic issues that are believed to be caused by the current tyres that flex more under load, producing different aerostructures that the Woking outfit did not anticipate. The airflow projected off of the sidewalls at speed and the wake that the tyres produce impinges on its surrounding components, changing the way they work compared to when they operate under laminar, straight oncoming flow. This is partly the reason why their car has to still run with this more basic layout, as the aerostructures interfere with the under-chassis vanes that they tried during pre-season testing.

More recently at the Young Driver Test (YDT), McLaren returned to trying out their triple element under-chassis turning vanes as they believe that the introduction of the new tyres, with stiffer side walls and therefore less flex, will benefit the aerodynamics of the car around this sensitive area.

Pillars

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With development rates slowing down, the wing pillars experienced some extra treatment. Teams started to extend the width of the pillars to the furthest point possible (in line with the trailing edge of the front wing endplate) from the pillar’s attachment point at the back of the wing’s main profile. They also tended to taper them inwards at their trailing edge to attempt to feed the turning vanes on the underside of the car.

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Ferrari have had the pioneering role in this area and have continued to develop the pillars this season. The pillars on the F138 start from the very tip of the nose, before sloping backwards to meet the back of the main plane of the front wing. The image above shows their second iteration of the design this year. The idea behind this is to work in conjunction with the extended width, guiding the air better through the underside of the car.

Mercedes and Williams have also followed suit with their own versions.

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Recently, McLaren tested their own version of the extended pillars at the YDT last week.

Pelican/Pregnant Noses

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A more recent development has been the introduction of the pelican, or pregnant, nose layout. This involves the formation of a rounded bulge directly beneath the nose to further force airflow beneath the chassis and into the floor.

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Lotus were the first to introduce this idea to their E21, but back in 2009 the same outfit, formerly known as Renault, had a very similar idea on their R29 which was then dubbed as a “snow plough”.

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Sauber have a slimmer but more pronounced bulge on the C32.

Although the pregnant nose is a good way of enhancing the floor, it also causes additional drag. So far we have seen teams using this component drop it for tracks that require low drag setups, such as Montreal in Canada. I expect the same at Monza in Italy. The additional downforce that is created from using this is not needed at these circuits. Because the bulge is formed into the nose during manufacturing, it is not a removable piece therefore separate noses must be made without the bulges for these events.

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