Tag Archives: t wing

Tech Highlights: Top aero features of 2017

As Formula 1 introduced a raft of changes ahead of the new season, 2017 was always likely to produce some new features on the aerodynamic front. Here are some of the key highlights from this year.

T-wings

The appearance of T-wings on this year’s cars is a consequence of the changing of the rear wing dimensions for 2017. During the rewriting of the rules a small region that was previously occupied by the outgoing higher rear wings was accidently left unattended. The extruded 50 x 750 mm area was instantly taken advantage of by the teams, with the majority of them converging on some form of twin element design by mid-season.

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Mercedes were one of the first teams to debut a T-wing in 2017

On its own the T-wing produces some downforce with minimal drag due to its wide span and extremely short 50 mm chord length. This in itself is a good enough reason to install one on the car, however it also has other positive implications.

An aerofoil with even a small amount of camber will generate an air pressure difference between its upper and lower surfaces. The air will try to equalise itself as quickly as possible, and the best way for it to do that is for the high pressure flow on top of the wing to flip underneath at the wing tips. This causes the air to rotate, generating a vortex due to the flow’s momentum.

The rear wing produces huge tip vortices due to its high angle of attack, which the teams try to control using endplates. Although the presence of a vortex indicates induced drag, they can beneficial to the car’s aerodynamics as they help pull airflow from elsewhere. You can either use them to pull air over bodywork to produce more downforce, or move turbulence away from more sensitive regions of the car (i.e. Y250 vortex).

The small tip vortex rolling up on one side of the T-wing travels backwards and entwines with its corresponding rear wing tip vortex behind, creating a slightly more powerful vortex overall. This amplifies its suction effect and therefore draws out more air from under the rear wing, thus enhancing rear downforce. It may only be worth a fraction of a second, less than a tenth. But considering its simplicity and minimal manufacturing cost, it is an item that’s definitely worth having.

Serrated bodywork

A lot of previously blocked areas of the car have been opened up for development for 2017, including the bargeboards and the floor surrounding them. While we expected to see the sprouting of flamboyant geometries and the arrangement of multiple turning vanes, it is still fascinating to see the intricate detailing that separates even the top teams.

In 2016 Mercedes started to play with serrated bodywork to manipulate the air more aggressively. Dividing an angled geometry into several sections allows flow to migrate between the two sides, reducing the chances of flow separation. In turn, mini vortices form across each section, which then all roll up into one powerful vortex projected aft of the bodywork. This trend has been carried into 2017: Mercedes have even chosen to stagger a series of mini turning vanes – each producing their own vortex – along the bargeboard’s footplate to provide the same effect.

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This technique can be found on other sections of the car too. Like a vertically mounted turning vane, the floor of the car has a pressure gradient between its upper and lower surfaces – this is due to ground effect. Serrating the floor/bargeboard footplate has become a popular choice for plenty of teams, including Force India, Ferrari and Renault (pictured), as it helps energise the air flowing along the flanks of the car. Air naturally wants to migrate underneath the car, and by introducing it in this fashion the direction and intensity of the flow can be further dictated. This will help seal the floor along the side of the car, allowing teams to run a higher rake angle.

Mercedes cape nose

The caped nose Mercedes introduced in Spain represents one of the most dramatic changes in frontal aero philosophy in recent years. Dubbed the cape due to its trailing, flared silhouette, its job is to direct clean air into the bargeboard area and enhance the Y250 vortex produced at the inboard section of the front wing. It replaces the common solution of a series of turning vanes that hang under the front bulkhead, which offers slightly less efficiency compared to the ‘mini diffuser’ geometry that the W08 now has.

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Image courtesy of Alessandro Berrageiz (@Berrageiz)

The cape’s lipped leading edge is designed to produce a vortex along its periphery, while the smooth underside – which hosts the inlet for the S-duct – aids the transition of laminar flow underneath the bodywork and out of the diffuser-like channels at the back.

The chances of seeing another rival introduce this solution before the end of the season are pretty slim, but it is perhaps something that we might see creep onto other cars from 2018 onwards.

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2017 Barcelona test (1) tech review

I don’t normally cover testing anymore but a big thank you to Charlie Stephenson (@myboringhandle) for letting me use some excellent photos he took from Barcelona last week. This short blog post will cover some general tech themes to look out for in 2017 and who I think is the fastest after the first test.

Shark fins and T-wings

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Love them or hate them, shark fins are (probably (depending on what Ross Brawn has to say in the near future)) here to stay this season. The lower and wider rear wings are in the firing line of  the turbulent wake coming off the front tyres and front wing, so a fin is used to manage the air over the rear of the car. They are particularly useful in yaw situations as the car’s wheels are turning and the wake is blocked from washing over the rear wing by the large bodywork.

Mercedes have taken things a step further by integrating a chimney into their fin – a small opening has been made into the top to cool the internals. Whilst the internal aero won’t so much be pushing hot air through it, the freestream flow above the car will pull out the higher pressure air inside the car.

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Then there’s the addition of T-wings. Funnily enough, this area of the car has been opened up completely by accident. Up until October there was no bounding box to allow for such devices but in the final release of the regulations somebody made a boo-boo and, of course, the teams have exploited it. T-wings are tiny winglets that help tidy up airflow ahead of the rear wing, kicking air upwards to help the aerostructures at the rear of the car. Williams (above image) have even put two devices on the car whilst Mercedes (below) have doubled them up to induce a greater effect.

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The Mercedes version bends over at the wing tips to prevent vortices forming, although some teams may actually prefer an open ended solution. Standalone devices such as on the Mercedes look ridiculous in my opinion but I’m not overly fussed if they sprout from the fin. This area of the car could be festooned with winglets and vanes by mid-season if the situation isn’t nipped in the bud soon.

 

Testing methods

We haven’t seen anything too outlandish in terms of sensors so far but the usual methods of checking whether on-track data aligns with that seen in the factory were very much evident at the first test.

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The larger front tyres have resulted in complex bargeboards and turning vanes to shield the sidepods and floor from turbulence. Large pitot tube arrays are mounted behind the tyre to assess the pressure and velocity of the wake and how it changes in cornering situations. This data can then be used to develop new aero devices around the cockpit, or adjusted to suit a new front wing design.

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Flow-visualisation paint (or flo-viz) is a paraffin based liquid that is used to map airflow over the car’s surface. This is particularly useful for getting a baseline understanding of how the air is being influenced by the car’s bodywork on track, which can be compared to flo-viz tests in the wind tunnel and stream traces in CFD simulations. It can also identify areas of flow separation.

The Force India above is absolutely plastered with the stuff. Use of the same colour can be quite revealing to prying eyes, especially in large quantities. Teams can also use various colour combinations of flo-viz to check for cross flow from different parts of the car.

Rake angle

Rake angle is the car’s front down, bottom up attitude relative to the track surface, and increasing this angle has huge benefits. Getting the splitter at the front of the car closer to the floor induces high speed flow along the floor, while a higher rear end essentially creates a larger diffuser for air to expand from. This combination produces a lot more downforce without a huge drag penalty – even a few millimeters of additional rake brings incredible performance gains.

OK, so why aren’t all the teams jacking up the rear ride height? Well, as rake angle goes up, the sides of the floor move away from the ground, which reduces ground effect as low pressure leaks from the underfloor. To increase rake angle you must also seal the floor using complex aerostructures that stem from the front wing. We often talk about the Y250 vortex for a reason: a stable vortex that can span a great distance along the car will improve the seal. The larger 2017 bargeboards and turning vanes will also help prevent high velocity flow escaping.

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Red Bull have long been the kings of using rake as their underlying aerodynamic concept. The relative simplicity of the RB13 compared to the Mercedes and the Ferrari should not be a sign of the team’s lack of creativity around the new regulations, as getting the car to sit the way it does in the above image takes a lot of work. Less complex bodywork will also decrease drag, an area that Red Bull have been working hard on in recent years.

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Although not quite as extreme as Red Bull, Ferrari are one of a number of teams that have also pursued extra rake to find more downforce. As you can see above, there is ever-increasing daylight between the car and the track the further rearward you look.

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McLaren stole Peter Prodromou from Red Bull in 2014 and his influence on the design of the car has become clearer over the past two seasons. Prodromou was Adrian Newey’s right hand man at Red Bull during their prime and his presence in Woking has definitely been felt judging by the MCL32 chassis design. Beautiful front wings, high rake angle and a degree of simplicity are all Red Bull trademarks finding their way onto the Woking cars. It’s a pity that Honda appear to be bloody useless again this year, but let’s wait and see on that…

So, who’s fastest at the moment?

Mercedes. Yes, they grabbed the headline time on Ultra-softs but their impressive long run pace and awesome reliability show just how mighty this team really are. I must admit that Ferrari have also looked pretty good so far and I’ve been impressed by Renault. Perhaps I’ll have a review of things next week to form a full pecking order before Melbourne. God, I’m excited!