In 2021, Formula 1 will move to new technical rules. The stated objectives are to make the racing competition tighter, and F1 cars look more aggressive. And although the adoption of the final rules has been postponed until the end of October 2020, the work on new cars is in full swing.
Due to the coronavirus, the global change in technical rules has been postponed until 2022, however, F1 cars will not be the same in the following season. What will be the changes, and who will benefit from them?
In May of this year, the Federation Internationale de l’Automobile (FIA) announced that in 2021, the teams will have to change the floor geometry on the sides of the chassis. It would seem a little nuance in aerodynamics, but this is exactly where a significant part of downforce is created.
Downforce, generated by the floor, is the multiplication of the floor area by negative air pressure generated there.
Technical Rules
- Individual car component reengineering freeze. The list includes the chassis, gearbox, a number of mechanical components, and safety power elements. A system of conditional points has been developed, which will allow upgrading a limited number of components to meet the specific needs of a particular team.
- In 2020, power pack reengineering is limited.
- 2021 introduces changes to the front bar and simplifies the underbody design in front of the rear wheels to prevent downforce growth between the 2020 and 2021 seasons.
- In 2021, the minimum weight of the machine increases to 1651 lbs (749 kg).
Sports Rules
- In 2020, the concept of a “closed” and “open” stage for spectators is introduced. This also regulates the number of employees that teams can take to the races.
- Various changes regarding tires in 2020 F1 rules. Permission to carry out tire tests during the second session of the Friday free races, if Pirelli needs to rejuvenate the new specification and extend the use of the P140 tire mark in case of the rain during the first free race.
- Limitations on wind tunnel testing in 2020 and limitations on power pack bench testing to reduce costs.
- Further reduction of wind tunnel tests in 2021 and introduction of a progressive time scale for wind tunnel tests, depending on the championship position of the team. The scale from first to tenth position is linear.
- A number of specific rules for the 2022 season has been defined. These rules, previously approved by the FIA on March 30, 2020, include component limitations, curfews, parc fermé (“closed park”) tests, and so on. The rules will be part of an ongoing review and refinement process throughout 2020 and 2021.
Before the German Grand Prix, the FIA working group conducted the first wind tunnel tests of the 2021 car prototype. A 50% scale model with 18-inch wheels was used for the tests.
A Sauber wind tunnel, which allows for more accurate results and comparison with CFD calculation data, was then rented in Hinwil, Switzerland.
The FIA believes that the model’s side-pods and rear wing will remain virtually unchanged, while work on the nose cone will continue.
Prototype types had to show whether the disturbance of airflow behind the car had been reduced, which would contribute to a tighter struggle on the track and, thus, an increase in the number of race leads (overtaking maneuvers).
According to Pat Symonds, Chief Technical Officer of Williams F1, the FIA was able to do it: “The results were even better than we expected at the start.”
Nowadays, teams can make the side edge of the floor absolutely straight from the cockpit to the rear wheel area, i.e. it can run lengthwise, parallel to the longitudinal axis of the car. But next year, when approaching the rear wheels, the floor will have to be 4″ (10 cm) closer to the chassis.
Thus, the sideline of the floor will not be straight (as it is now) but diagonal. This change will significantly reduce the total floor area, depending on the length of the wheelbase. In turn, as you remember, downforce, generated in the floor area, is a multiplication of the floor area by negative air pressure generated in that area.
Later we will explain exactly how the truncation of the floor will affect landing gear downforce. In the meantime, find out what the Head of Aerodynamics at Formula One Management Limited, Jason Somerville, had to say about this.
“By reducing the floor area, we’ve deprived the chassis of some of its downforce,” said the specialist. “F1 cars will lose downforce in high-speed turns due to maximum tire loads. And there are many of those, for example, in Barcelona and Spa. Of course, the teams will try to regain some of downforce they will lose but it is unlikely they will be able to compensate for losses to the current level – the cars of the 2021 season will not look the same, as the teams will continue to improve them.”
How exactly can floor geometry have such a significant impact on the aerodynamics of the chassis?
The thing is that the restrictions will affect not only the floor but all the slots, the number and geometry of which played a very important role, precisely verified by the teams.
In this part of the floor, the slots are subdivided into longitudinal and transverse, performing completely different functions, although aimed at increasing downforce. It is expected that geometry changes in the floor and the slots together should increase the average lap time by about half a second.
Why so much, you ask?
Well, here, we need to understand the purpose of the slots in this part of the floor.
Cross slots, located directly in front of the rear wheels, are designed to divert excess air mass, generated in this area, from the chassis by wheel rotation. In the absence of these slots, the airflow running along the floor will be affected by vortexes generated by the running wheels, resulting in a so-called “head-wave effect.”
This barrier will significantly reduce the volume, speed, and airflow smoothness to the cone, which will seriously reduce its efficiency. Obviously, anything that prevents airflow from moving along and below the floor has a negative impact on downforce.
So these cross floor slots became popular in the modern Formula 1 fashion for a reason, and the teams paid increased attention to them, changing their geometry from stage to stage.
Simply put, these slots allowed the air formation coming from the rotating wheels to be sent far away so that it did not interfere with the “clean” airflow along the floor to the cone.
The long longitudinal slots along the entire lateral edge of the floor, which have become very popular in Formula 1 over the past year, serve to create vortexes along the entire floor edge. Thus, they artificially form the “skirt” that prevents air mass from escaping from under the floor to the sides.
This, in turn, allows increasing the pressure differential between the chassis and outside. The idea is old, and the implementation is new.
Next year, aerodynamic specialists in teams will no longer have an opportunity to rely on the help of these two types of slots to increase the aerodynamic efficiency of the car when adapting the chassis to the new season. But no one forbids them to modify the chassis in the wing, side-pods, and cone areas in order to somehow compensate for the forthcoming restrictions of technical regulations on the floor side edges.
Why did the FIA impose a ban on the slots in the floor and change its geometry?
This is a kind of measure to counteract the future natural development of teams to increase landing gear downforce. The fact that the transition to new Pirelli tires with 18-inch rims was also postponed until 2022, which means that in the next season, the cars will have current tires installed, which are already at their resistance limit to aerodynamic loads.
Reducing downforce in tight corners was simply necessary so that the tires could still stay in the optimum working door.
Initially, the FIA wanted to reduce downforce by reducing the area of the rear wing. But during the modeling of this system, it turned out that this option would not work. The fact is that the wide chassis, which appeared in 2017, by itself creates such a huge downforce that, most of the times, racers can corner at high speeds.
And if you reduce the rear wing, the speed in those corners will increase even more, and you can still go at full speed.
How will this innovation in the rules affect the chassis of different teams?
Of course, over time, engineers will understand how to overcome new constraints and get to the previous level just as they always do.
But in general, we can say that in the first simulations, the teams whose chassis have a flatter floor (e.g. Red Bull) should feel more adversely affected by the cut sides of the floor than those teams whose chassis have a flatter floor (e.g. Mercedes and Racing Point).
If we remember that downforce generated by the floor is a multiplication of the floor area by negative air pressure, it becomes clear that F1 cars with a smaller wedge, a larger floor area can be used to compensate for the lack of negative air pressure per square inch, compared to the chassis with a high wedge.
According to Jim Malkovich from Mechanic FAQ, removing the “blocking” longitudinal slots from the floor will reduce the limit negative air pressure that can be created with the floor. Well, that’ll be speculations. Let’s see how Formula 1 engineer teams handle this daunting task.
Author Bio:
Dale Lomas is Automotive fan, journalist, photographer, racer and Ring Taxi driver. Now his own and run the largest unofficial Nürburgring fan sites BridgeToGantry.com.
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