F1 upgrades: How are aerodynamic upgrades planned and deployed?

Every race weekend, we bear witness to a very public battle across various circuits worldwide, with drivers pushing their race cars to the limits; limits dictated by the capabilities of the machinery they are piloting.

However, day in and day out there is a much more secretive battle taking place across the factories of each constructor to gain a competitive advantage over the rest of the field. In this article we will explore how teams seek to gain this advantage through aerodynamic development.

So, how are aerodynamic upgrades developed and deployed across the season?

Formulating a plan
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At the very highest level, the intention of every upgrade is to improve the car’s competitiveness.

When developing the aerodynamics of a racecar, however, this must also come with a more targeted plan of what changes need to be made to the airflow to mitigate any shortcomings of the current package and to extract more performance.

Despite the latest set of regulations simplifying – or outright removing – many of the complex devices featured on the cars of previous years, the flow field around an F1 car remains extremely complex. Add to this the changes in the airflow around the car as it negotiates a variety of cornering and straight-line conditions, and the complexity grows in orders of magnitude.

Thankfully, there is a tool used by every aerodynamics department across the grid which can begin to help build an understanding of exactly what is taking place.

Computational Fluid Dynamics
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Often colloquially termed the ‘virtual windtunnel’, Computational Fluid Dynamics (CFD) plays a pivotal role in aerodynamic development. As the name alludes to, CFD involves the computation of a series of mathematical equations to simulate the flow field around any given geometry.

What makes CFD so powerful is its ability to allow aerodynamicists to visualise the flow field around the racecar. Features such as tyre wakes and vortices can be tracked from their formation all the way downstream to the rear of the car.

Another key advantage that CFD has is its relatively fast turnaround time. To simulate in CFD requires no physical building of parts, and results are generally available in the order of hours based on digital Computer Aided Design (CAD) data alone. Given the iterative nature of constantly tweaking every last detail to maximise any potential, this offers a huge benefit when developing an upgrade.

One disadvantage of CFD is that it is built from mathematical models and as such offers only an approximation – albeit an extremely good one – to real world flow physics. There are teams within aerodynamics departments dedicated to fine tuning the CFD ‘recipe’, seeking to bridge the gap between the virtual and physical. The number of geometries and computational power teams can put through this process is also subject to limitations set by the regulations.

Windtunnel testing

Another tool available for proving out any potential upgrades is the windtunnel. Whether on their own site or elsewhere, every team makes use of a tunnel to further their understanding of how the changes they make will impact the car’s aerodynamic performance.

Given the much lower resource requirements of CFD, geometries put forward for tunnel testing will have typically been tested and refined virtually before being committed to a physical build for the model. By this stage, the candidate geometry will have been designed to be tested at scale (currently regulations limit the model to 60% scale), built most typically using rapid prototyping (RP) methods, and then hand-finished in the model shop.

Once the new geometry is installed on the model, it will then be run through a series of pre-defined setpoints known as an ‘aerodynamic map’. This map will modify the pitch, roll, yaw and steer of the model to replicate a variety of on-track conditions.

While CFD offers results in hours, the turnaround time for windtunnel results can be days, if not weeks for larger programs owing to the design and build requirements. Regulations also impose limits on how much time teams can spend using their windtunnel.

Track testing

Typically, an upgrade package will have undergone weeks, if not months, of iterative testing and refinement through CFD and the windtunnel before it is released to the design office and makes its way to the track. Only once enough confidence is built up in how a package will perform will the full resources involved in designing, manufacturing and then testing be committed.

While the windtunnel can mitigate the requirements and timescales involved in physical builds using rapid prototyping methods, components on the car are often manufactured using materials such as carbon fibre, which are both costly and labour-intensive to prepare. Testing opportunities are also limited, with any new packages having to jostle for time slots in amongst the usual set-up run plans taking place during free practice sessions.


Track conditions are ever-changing and a subtle change in wind direction or the driver taking a different line all adds noise into the dataset. Data from across the lap may also show the package to be working under some conditions but having a detriment in others.

Correlation

Whatever the outcome, once the entire process has been completed, it is time to pore through the data and determine how well (or otherwise) the simulation tools were able to predict the outcome.

F1 cars run an array of instrumentation on their surface known as ‘pressure tappings’.

These small holes, typically located on the underside of the wings and floors, can record the pressure across the aerodynamic surfaces and provide a detailed map of where the aerodynamic loads are being generated and any changes taking place.

Aerodynamic rakes attached to the car during free practice sessions can also gather data about the airflow features away from the surface.

Using this data, aerodynamicists are able to directly compare back to their CFD and windtunnel datasets and pinpoint any areas of miscorrelation to target.

Continuous improvement

The process described above operates as a continuous loop; whilst one upgrade is being pushed out of the door, another one is already well under development.

The current cost-cap regulations have forced teams to become more targeted in their approach to upgrades, with correlation being even more critical in ensuring a higher hit rate once parts hit the track.

With each iteration, the aerodynamicists begin to understand and realise the potential of the overall package.

Aggregating every marginal gain available allows teams to improve their competitiveness and climb the order. Or at the very least, maintain their status quo.