Why F1 shouldn't be too rigid about flexi-wings

The science of aerodynamics and the particular impact it has on Formula 1's vehicles always has offered interesting opportunities for debates.

To make it straight and simple, every driver and F1 engineer would dream of having all the downforce in the corners (grip-limited areas) and the lowest downforce level on the straights to get the maximum possible top speed. But in life there is always a cost and in aerodynamics the cost of downforce is called drag.

With fixed wings, as stipulated by F1’s rules, there is no easy way to be in the sweet spot for each sector of a race track and this is why overtaking has been so difficult. It goes some way to explaining why the DRS (Drag Reduction System) was introduced to improve the show.

DRS: In defence of an unpopular F1 overtaking aid

So far, none of this generates arguments. But there is a grey area, as the FIA defines the level of stiffness for many parts around the car in order to have a fixed behaviour of the aerodynamics at speed.

The teams can vary the downforce dynamics only through a limited amount of settings such as angles of attack (ie front flap angles), wing surfaces and rake (difference between rear and front rideheight) for a given aero map.

Red Bull Racing RB14B front wing detail

Photo by: Uncredited

The reason why the FIA keeps this sort of monitoring is because aeroelasticity is a complex science and complex technologies are expensive and risky if a team gets it wrong. Conversely, we heard about a proposal for active aerodynamics which is where I personally get a bit confused. This is what suggested me to draw the conclusion I share at the end of this article.

Going back to our overview of the story, there is a category of teams that try to push the boundaries of the rules. And their competitors claim they are cheating!

In the words of the FIA technical director Nikolas Tombazis, this static test is not adequate as it is not representative of all the real load profile the wings are seeing

With ‘flexi wings’, the aim is to flex the aero wings in order to reduce the drag level as the speed rises by reducing the cross-sectional area (Drag Force= Constant (air density) x Drag Coefficient x Velocity^2 x Area). This is why a rear wing for Monaco has a broader sectional area compared to a rear wing for Monza (the highest top speed of the calendar).

From an operational standpoint, FIA checks the aero parts stiffness by applying a load and measuring the displacement. In the words of the FIA technical director Nikolas Tombazis, this static test is not adequate as it is not representative of all the real load profile the wings are seeing. 

Ferrari SF21 rear wing detail

Photo by: Giorgio Piola

This explains why the teams are still able to pass the FIA tests while allowing wing flexibility. And there are multiple strategies for that:

A. Designing a wing stiffness into the supports in order to reduce stiffness especially beyond the FIA load applied during the scrutineering tests. The stiffness curve is designed to be progressively decreasing especially after a load threshold;

B. Letting the rear endplates or the pylon (where the rain light is mounted) bend. This changes the cross-sectional area of all the rear aero parts with the speed;

C. Closing the gap between the main wing and the upper rear flap. By doing this, the air flowing underneath the main wing will suddenly encounter a higher camber with no added energising air flow (through the gap). Therefore, beyond a certain speed, we will see a stall of the rear wing. This means the rear load due to the rear wing will be significantly reduced.

For the front wing, two benefits are pursued by introducing aero flexibility. The front wing provides front load/grip, balance and has an increasingly important role in preparing the air flow for the rear and lower part of the car. Two goals are chased in this area:

- by lowering both sides of the front wing the engineers increase the ground-effect, which improves the floor flow;

- by bending the upper flaps rearwards with the speed, the goal is to stabilise the entry of the corners and improve the flow around the car.

Aston Martin AMR21 high downforce rear wing and rear brakes detail

Photo by: Uncredited

I’d like to share a provocation on this topic to invite F1 not to be too rigid about flexible wings (please excuse the pun!).

At the beginning of 2020, the Japanese government became the first to allow OEMs to design cars with no rear view mirrors but using electronic devices instead. Speaking about drag, if you consider the cross-sectional area of a road car the impact of rear view mirror is about 20% on drag reduction.

This implies less energy to move a vehicle. This decision has been made possible by the advancement of the vision technology that now allows good resolution levels and adds extra features such as blind spot detection, night vision and so forth.

I strongly believe that today’s competence and assets in F1 would be very beneficial for engineering the cars of the future

I strongly believe that today’s competence and assets in F1 would be very beneficial for engineering the cars of the future. Surely, the hard work would be on the FIA to regulate materials and new constraints. Let’s get creative here and draft some rules:

- only natural fibre composites be allowed for aero appendages;
- a displacement range of a maximum Xmm is allowed between 150km/h (93mph) and 300km/h (186mph);
- beyond 300km/h aero parts need to be fixed.

This application would have a straightforward impact, especially in an automotive world striving for more aero efficiency while it is designing its way out of combustion to fit different forms of propulsion technologies at an earlier stage of their development curve. And what if engineers could find a way to harvest energy from the bodywork movements?

I hope the budget cap will never be so tough as to discourage these incredible opportunities for FIA and F1 to contribute to society.

Front wings and bodywork panels outside the McLaren garage

Photo by: Glenn Dunbar / Motorsport Images