12 May 2020

GOING BACK TO GROUND EFFECT

It’s been said in motor sport circles before that Colin Chapman had a lot to answer for. Take that as you wish, but what is undeniable was his single-minded approach to engineering innovation that made Lotus a dominant team through numerous eras of Formula 1.

Some innovations were more successful than others. Lotus’ forays into IndyCars sparked two concepts worthy of a mention. The Lotus 56 powered by a Pratt & Witney turbine engine and the Lotus 64 running a reverse mounted engine and 4-wheel drive both showed promise, but their competitive lives proved short lived, mainly due to reliability issues and then falling foul of rule changes.

Other engineering design concepts like the monocoque chassis construction of the Lotus 25, and the game changing stressed-member drivetrain (Ford DFV engine), of the Lotus 49, became standard practice in Formula 1 design, and it’s a testament to the impact they had that both techniques are still in use today.

However, one design concept that had the greatest step change impact on Formula 1 performance was undoubtedly the introduction of Ground Effect.

In the late 60’s Lotus had introduced wings to their cars. In the early days these were nothing more than inverted aircraft style designs employed to create more downforce on to the track through the tyres and as such create better handling in corners without adding more mechanical weight. Throughout the first half of the 70’s that’s where the technology stayed albeit as a greater understanding of wing design developed up and down the pit lane, so did the intricacy of the wing profiles and the associated drag that these designs created. That was until 1978 and the unveiling of the Lotus 78.

For some time, partly down to an accidental discovery in the wind tunnel, Lotus had been paying as much attention to air flowing under the car as the air flowing over it. Research had told the clever guys at Lotus that if they could control the air under the car to work in tandem with air flowing over it, they could create huge amounts of downforce many times that of the downforce generated from purely using the air flowing over the car.

They came up with a design that has since entered into Formula 1 folklore; the side skirt. By partitioning and channelling the air flowing under the car, the air pressure under the car was significantly reduced, making the air flow over the car more efficient in creating downforce whilst reducing drag and increasing top speeds. The whole car became to all intents and purposes a single wing.

As more teams adopted the technique, the Ground Effect R&D curve steepened significantly, and more and more innovative car designs made it to the track. By 1980, when eyebrows were starting to be raised as to cornering speeds and safety, most of the teams on the grid had dispensed with front wings as surplus to requirements.

Concerns over safety, became the death knell for Ground Effect. With the introduction of turbo engined cars requiring greater fuel loads, heavier ground effect cars cornering at frightening speeds arguable caused the deaths of both Patrick Depailler and Gilles Villeneuve.

Ground effect was in fact banned on 2 occasions. In 1981, FISA banned skirts but a loophole cleverly spotted by Gordon Murray at Ferrari allowed cars to raise their skirts for scrutineering and then lowering them once on the grid. For the 1982 season FISA briefly relented on skirts but then banned them altogether for the beginning of the 1983 season following the deaths of Villeneuve, Riccardo Paletti, and the almost fatal crash of Didier Pironi.

So why are we returning to ground effect and how is it different from 40 years ago?

After the banning of ground effect at the end of the 1982 season, all teams refocused their efforts on the air flowing over the car. The constant development and sophistication involved in Formula 1 aero packages to manage airflow over the car has created some undesirable side effects. The biggest of these undesirables has been the air disruption behind the car which causes following cars’ aero packages to perform at significantly lower efficiency, reducing the opportunities to compete and overtake, and in turn making racing more processional.

However, considering the safety concerns which led to the previous ban, what else has changed to make it viable for 2021?

Well first and foremost Formula 1 is a much safer sport than the seat of the pants days of the early 80’s. Car designs are much more stringently tested and both driver and spectator safety is paramount.

Secondly the return of ground effect in 2021 will not mean the return of skirts! With the introduction of composites and improvements in manufacturing, more streamlined and less “agricultural” ground effect techniques can be employed making venturi tunnels more efficient in the management of airflow and creating the desired low air pressures under the car. With the undercar “tea-tray” that comprises the Venturi tunnels being standardised a further layer of safety integrity can be assured.

In place of skirts a taller rear diffuser mounted on the rear suspension/brake duct assembly of the car will create the efficiency that was once provided by skirts to the first generation of F1 Ground Effect cars. However, with the diffuser mounted on this assembly it won’t be subject to changes in ride height between the main undertray and the track. This clever design means that fear of skirts failing at high corner speeds, which was a key reason for the original ban, has been removed.

These dramatic changes for 2021 will have the direct result that front and rear wings will not be required to deliver such downforce as before so can be simplified creating less turbulent air at the rear of the car.

If these changes prove successful it’s also highly likely that the need for artificial aids to overtaking such as DRS, will also be surplus to requirements.

In 2021 the Formula 1 regulations will be changing significantly contributing to what is expected to be a very exciting and closely run season. If you would like to experience the very best hospitality at one of the marquee races this year please contact JDC Promotions and let us build a bespoke package for you and your guests.

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ianhucklesby

Editor-in-Residence, JDC Promotions Media Centre