Despite changes aimed at improving the racing this year, current F1 cars lose 50% of their downforce when running behind another car.

Formula 1 plans to change that with a radical overhaul of car design in two years’ time. F1 motorsport director Ross Brawn has said some of their concepts for 2021 lose as little as 5% of their downforce in the slipstream of another car.

How is F1 planning to revolutionise the quality of racing in the championship? And what changes are they considering to bring about this change?

Craig Scarborough takes a close look at India, one of the concept designs for the 2021 F1 season, to find out.

We are now nearing the point where the final plans for the 2021 F1 regulations will be made public. To get to this point, the FIA with Liberty and FOM have been working in a new way to decide the technical direction of F1.

Under the leadership of Ross Brawn, a technical research and development group has been created and, for the first time, the rules will have been thoroughly researched and qualified before their release.

To do this Brawn’s technical team have had simulation programmes running to meet the aims given to them by Liberty, the primary aim being making it easier to follow another car and thus making it easier to overtake. The secondary aims are equalising the field, reducing costs and improving the aesthetics of the cars.

Along the way the teams have been assisting Brawn with further CFD research on a series of car concepts, the current model being called ‘India’, apparently as the ninth version, with “I” being the ninth letter of the alphabet. Looking at the ‘India’ car CFD model, we can see the direction that the sport is thinking of going in, although some of the final details may be missing or current details deleted. Taking the model at face value we can analyse how F1 aero might work in the future.

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Firstly, the key issues the Brawn group have worked on are reducing the sensitivity of the car’s downforce-producing surfaces when following another, then reducing the wake generated by the car ahead. These can be opposing requirements, but the model appears to have met these basic aims by shifting downforce creation to larger underfloor tunnels, while cleaning up wake by the simplification of the aero, with a few additional aero solutions to make the car’s wake cleaner.

Creating downforce

While the ‘India’ car at first looks similar to a current F1 car, albeit with some IndyCar influences, it’s the underfloor that’s changed the most significantly. Now the floor generates the majority of the aero load, while the wings have been reduced in their influence.

Current F1 floors feature a step along the centre of the car to lift the diffuser clear of the floor, to reduce its performance and sensitivity. Now, the floor of the monocoque and sidepods are on one plane, still with a plank along the centreline, but with larger tunnels. The most obvious change is the leading edge of the floor featuring a raised venturi inlet with the vanes inside acting as bargeboards to control the airflow through the floor to improve the downforce produced from ground effect.

To keep the up-wash from the front wing from upsetting the underfloor inlet, there is a triangular vane fitted amongst the front suspension. This will turn this airflow downwards and direct it into the underfloor tunnels

A hangover from rules dating back to 1983 is the flat floor under the raised footwell section of monocoque, demands for this floor section created the front splitter or Tea-Tray under the car. This has been deleted and the “V” shape under the monocoque is visible, its removal being to clean up the area ahead of the shaped underfloor.

At the rear the diffuser is a little longer and taller, but is far from a full-length ground effect tunnel as seen in the early eighties, this leaves a flat floor in between the ramped sections.

It’s thought that the underfloor venturi effect is less sensitive to the wake of a leading car and equally can be made to produce less wake, making this an obvious choice for the new car, although this will have been validated by Brawn’s group with CFD studies. In a further benefit the long floor will generate downforce both at the rear and the front, creating an equal balance of downforce front to rear.

Back in the eighties, the long ground effect tunnels were effective as skirts sealed the low pressure beneath the floor. Skirts helped make huge amounts of downforce, but at the same made the car sensitive to bumps and kerbs, as any low pressure was lost when they lost contact with the track surface.

Therefore, skirts were not reintroduced for the ‘India’ car, but instead a pair of vanes flank the rear diffuser tunnel, these vanes being much lower than the floor of the car to help seal the diffuser. Hanging some 10 centimetres below the floor, what’s surprising about these vanes is that they are mounted to the rear brake ducts, thus will move with suspension movement, remaining close to the ground at all times aside from any tyre movement. In this guise the vanes should be very effective at sealing the underfloor without adding sensitivity as experienced with skirts.

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Another problem with powerful diffusers at the rear of the car is that high-pressure air spilling off the rear tyres gets directed the low-pressure area inside the diffuser ruining its performance. This issue known as ‘tyre squirt’ has been fixed in the past ten years with; shaped floor sections, exhaust blowing and latterly slotted floor edges. Evident on the ‘India’ model is a return to the scalloped section and a complete lack of any other floor edge slots, serrations or add-ons. This scalloped section will send a blast of airflow in between the floor and tyre to reduce the negative effect of tyre squirt.

Given the increased desire to equalise the cars and reduce costs, one wonders if the shaped underfloor will be a spec part, either made by a third party, or made by the teams to a FIA template?

In adopting the shaped underfloor format, the front and rear wings have been clipped significantly, the front wing is still at the car’s full two metre width, which is the same as the current cars and the rear wing narrowed compared to the current wings.

The front wing follows the path established by Brawn’s changes with the 2019 rules, now reduced to just three elements spanning all the way from the nose to the endplate. This discards the ‘Overtaking Working Group’ 2009 concept of a neutral centre section hanging from a raised nose. In the frontal CFD picture seen here, the wing looks unusually high, but this is a trick of the eye, the viewing angle of image has the car positioned horizontal, so the front wheels are up in the air and not at ground level, it appears the front wing height will be similar the current set up.

Its unusual that the wing is split by the nose, it might be a nod to the early nineties F1 designs, but is actually a wake reduction trick. On the post-2009 front wings, the intersection between the neutral centre span and the outer wing shapes produces the Y250 vortex. This is an outwash trick exploited since 2009 to push the front tyre wake outboard. Without this intersection or any means to shape the wing in this area will greatly reduce the outwash effect and clean up the car’s wake.

At the rear the wing is quite unusual, as its stylised appearance does away with separate flat endplates joining the wing profiles. This may be another aesthetic trick, but the lack of endplate above the top wing elements will reduce downforce and the wake formed at its wingtips. Also, the wing sees the return of the lower beam wing, in this case, it appears to be acting as an extension to the underfloor tunnels. On this model at least, there is no DRS, the theory is that these cars should be able to overtake legitimately without it.

Reducing turbulence

The cars turbulent wake will have already been reduced by the simpler wings and underfloor tunnels, but a great proportion of the cars wake is produced by the wheels themselves. It seems fans and F1 itself are sensitive to remain an ‘open wheel’ format, or rather exposed tyres. Again, Brawn’s research team focussed on front tyre wake with the 2019 F1 regulations, ‘India’ goes a step further in reducing this.

Firstly, there are wheel covers, closing off the outer face of the wheel with a flat disc. It’s not clear if there are attached to and spin with the wheel or if they are 2008-style static covers that do not spin. These will greatly reduce turbulence as the wheel wake will flow smoothly along the wheel cover’s surface and not break up over an open wheel design. There remains the issue of brake cooling with this design, that isn’t resolved with the model seen here. Perhaps the brake heat is ducted through inside face of the wheel, rather than through the outer face. It’s also notable that the brake duct also features a lower mounted vane, banned this year, to help clean up the tyre wake as is flows along the inner brake duct.

Likewise, the rear brake ducts are reshaped, not just with the diffuser sealing vanes, but the duct flows back behind the wheel to the rear edge of the tyre, this should help clean up the wake behind the rear tyres.

Another tyre wake trick is the ‘blade’ mounted over the top of the tyre, this small piece of bodywork will be hugely influential in reducing tyre wake as it will delay the break-up of airflow behind the tyre. Although some fans have expressed this as un-F1 as it partially covers the tyre.

With this cleaner tyre wake, along with the loss of the Y250 vortex, the reduction in the front wing endplate outwash effect and lack of powerful bargeboards means whatever wake is created by the front tyre will be pulled into the coke bottle area and not pushed outside the rear tyres creating a narrower wake behind the car, thus easier for the following car to get closer.

Other features

Aside from the headline downforce and turbulence tricks on the ‘India’ car, there are some other less obvious features that may also give an indication of a desire to make the cars look different to each other. Additionally, there are many unanswered questions as regards what lies beneath the bodywork.

Since 2012 F1 noses have been subject to rules to lower their height and enforce a mandatory cross-sectional area. With stepped noses, shifting towards the 2014 finger noses and the current thumb-tip noses. This car still features a long, low-tipped nose, but no awkward nose tip is adopted, so hopefully we should get some better-looking designs in this area.

Equally the chassis cross-section where it meets the nosecone has been a distinctly square-edged rectangular shape since the late nineties. This is now more rounded on the 2021 car, perhaps the rules will be less explicit in the cross-section area leading to more appealing rounded designs in the future.

Also, a small shark fin is also included on the CFD model, in this size and shape it would certainly help the rear wing aero through corners, but also adds an element of visual interest to the car.

It seems the sidepods are the least considered area on the ‘India’ concept, these are conventional mid-positioned inlet designs with a stylised lead-in to the inlet. There appears to be no side impact structures integrated into the shape, either as this is an early iteration of the car, or perhaps that the shape of these spars mounted to the flank of the monocoque are changing for 2021.

Beneath the skin, the power units are not now expected to change significantly for 2021, but a more radical shake up of the Engine/ERS format has been delayed. Meanwhile gearboxes are believed to go with a single-supplier fixed-specification for this season too, reduced to a seven-speed unit within a self-contained cartridge, leaving teams to design their own outer casing to join the suspension, rear crash structure and gearbox to the rear of the engine.

Other fixed specialisation parts are likely too, perhaps brake calipers, brake disc and pad material, suspension uprights or even wheels. While other innovations such as a return to a fixed hardware-spec active suspension set up and electronic rear-view mirrors.

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Summary

From these images it’s clear that opinion is split on the looks of the car, the validity of wheel covers and the tyre ‘blade’. Furthermore, it’s not apparent if the extreme wheelbases and heavy weight of current F1 cars will be resolved by these rules.

But F1 has for the first time a set of properly conceived, researched and validated rules that should deliver on the requirements set out for them.

Video: F1’s 2021 aerodynamic concept

F1 technology