What the first look at 2021's F1 aero rules tells us

As the 2020 Formula 1 season winds into its final five rounds, we already have our first clue into how next year's cars will look. Although this year's chassis will be carried over into 2021, thanks to the financial consequences of the COVID-19 pandemic, there are a few changes that must be made to cut the overall downforce produced.

The technical overhaul ushering in the return of ground effect cars will have to wait until 2022 and the introduction of Pirelli's 18-inch tyres will also be delayed, meaning that the tyres designed for 2019 will get yet another year of service. There are a few aerodynamic changes to address this for next year, including the removal of part of the floor and from the diffuser, estimated to bring a 10% reduction in overall downforce to ensure the Pirelli tyres work within the load window intended.

Without those changes, tyres designed for 2019 aero loads would be forced to then work under the increased downforce added by two years of aero progress. Although Pirelli can increase the tyre pressures, as it has done on certain occasions in 2020, it would risk having to inflate them further and risk running them in a condition they were not designed for.

That's not any slight on Pirelli at all, as the tyre manufacturer has the arguably the most thankless task in motorsport. Rather, it does the Italian company a bit of a favour, saving it the expense of developing an entirely new tyre for one season. Of course, had the teams decided not to veto Pirelli's attempted 2020 tyre construction, we might not have any aero changes at all - but that's a different story altogether...

Ferrari tried a new floor and diffuser in practice for the Portuguese Grand Prix in order to explore those changes, and provided F1's onlookers with the first proper look at what's possible within the bounds of the new rules.

The first involves the triangular cut out from the floor when looked at in the plan view of the car. This means that a multitude of the slots and cuts in the floor will either be eliminated due to the section of floor cut out, or due to new rules on "continuity" of bodywork. Ferrari has shown a representation of what the floors may look like next year, as it tapers inwards and does not cover as much of the rear tyre as it previously did.

Removing those slots limits some of the protection that the diffuser has from the turbulence produced by those rear tyres, and so Ferrari has attempted to mitigate some of that by creating a curled-up trailing corner of the floor. This may be a bid to create some kind of tip vortex, which could theoretically roll inboard and protect the diffuser. It doesn't have quite the same ability to create a seal around the floor - indeed, that's the very idea of these changes - but it should go some way towards helping recoup some of the downforce.

The diffuser will also lose 50mm from the length of the inside fences - meaning that they are less protected from turbulence and aren't as well sealed as they currently are. Ferrari has trialled that too, taking that away from the slotted fences within - which are broken up to coax the airflow into forming a larger expansion zone.

As one F1 designer described, it's a little bit like taking a hacksaw to the current cars - and the consequences of that hacksaw must not be underestimated

2021's aerodynamic tweaks are to peg the teams back in the anticipation that, over the winter and during season, they will recoup that lost downforce. Although the retention of this year's chassis has probably changed the usual timeframe in which a car is designed and built, teams are beginning to think now about that process - in fact, Toto Wolff admitted during the Eifel GP weekend that Mercedes had stopped bringing parts for 2020 "a long time ago" in order to focus on the aero changes for next year.

Attempting to understand the effects of these changes now should help Ferrari, armed with a few practice laps on 2021-spec aero, overturn some of the issues with its SF1000 earlier with greater development time. With Friday practice all about correlating wind tunnel and CFD data with real-time on-track performance, expect further teams to use the practice time available - most likely in the final four rounds - to build and develop 2021-style parts to understand next year's effects.

As one F1 designer described, it's a little bit like taking a hacksaw to the current cars - and the consequences of that hacksaw must not be underestimated.

Ferrari wasn't the only team with enough foresight to look into 2021's mandatory developments in Portugal; Mercedes also spent the entirety of Friday running in a partial '21-spec to coincide with FP2's tyre test.

Rather than focusing on the aerodynamic implications, Mercedes has its own battle to fight for next year in the prescribed removal of its dual-axis steering system. DAS will be outlawed next year, meaning that Mercedes loses one of its tools to bring its front tyres up to temperature by changing the toe angle a couple of degrees for a more complete warm-up.

The W11 was conceived to host both DAS and a conventional steering set-up, and although it meant Mercedes' mechanics had to spend time building up and dismantling one system for the other, it meant that Lewis Hamilton and Valtteri Bottas could reacquaint themselves with a DAS-less existence in time for next year.

Losing the system won't be the end of the world for Mercedes, but it does mean that the vehicle dynamicists and suspension designers based in Brackley will have to spend time finding a way to replace that passively with the load paths that they put through the tyres.

Mercedes cantered to victory in Portugal, Hamilton beating Bottas by over 25s, but there have been momentary periods over the past few races where it appears that Red Bull has lost a small portion of its deficit. Maintaining a high rate of development, Red Bull has continued to explore the limits of its RB16 and introduce some interesting innovations.

Firstly, the team has opted for the small split channel in the rear suspension upper mounting, where the top wishbone connects to the upright. This is a design that Mercedes explored last year, and seems to be a way of breaking up the mounting point to channel airflow into an area that usually sustains some kind of blockage from the suspension components.

When Mercedes introduced a similar design last year, it did so to a backdrop of queries to the FIA from the other teams over its legality. Usually, that's a precursor to getting a design outlawed or, in this case, having the confirmation from the FIA to develop their own solutions.

But Red Bull has also developed a new front wing too, featuring a rather novel innovation. Underneath, the wing features a slot on the underside of the endplate, while two small holes appear on the trailing edge of each front wing endplate.

This draws air through the construction of the wing and releases it at the point where air is being turned around the front of the wheel. By transferring the airflow from a larger inlet underneath to a smaller outlet, this will accelerate the airflow coming out - as per Bernoulli's principle. In response, the fluid pressure within will drop.

Although 2020 is drawing to a close, the unique situation of being obliged to carry over cars into next year means that every avenue of development is being explored

This seems to be a way of strengthening the airflow released off the top corner of the endplate, which will further assist the outwashing characteristic that the curvature of the endplates provides.

Think of it like a Super Soaker. The container that the water is in has a larger diameter, and has a larger pressure compared to the nozzle. To balance that out, the jet of water passing through the nozzle moves at a much faster speed - as per the continuity equation. In the case of Red Bull's front wing, airflow is then drawn to that jet of fluid, owing to its lower pressure, and can then be manoeuvred around the front tyre.

Ultimately, the holes are very tiny in size, but this is a novel approach to Red Bull's aerodynamic development, and sidesteps many of the restrictive regulations governing the front wing's shape and size by using the internal construction.

Although 2020 is drawing to a close, the unique situation of being obliged to carry over cars into next year means that every avenue of development is being explored. A lot of the development work will, as Ferrari and Mercedes have proved, go into nullifying the effects of 2021's "hacksaw" aero regulations - but as Red Bull is demonstrating, there should be plenty of life in these old dogs yet.