Formula 1’s proposed 2021 technical regulations are being refined, with aerodynamic testing currently underway to ensure correlation of collected data.
While the upcoming 2021 rule changes haven’t yet fully confirmed the technical regulations, a general philosophy of improving airflow and reducing turbulence is one of the key goals for the new designs.
Using computational fluid dynamics (CFD), a basic design has been modeled using a 50% scale. Last month, ahead of the German Grand Prix, this model was tested out in Sauber’s wind tunnel in Switzerland. The test was carried out by an independent consultancy group run by Sauber, meaning that the Alfa Romeo team won’t gain any early extra knowledge or advantage as a result.
The wind tunnel tests were run to confirm real-world data alongside the simulated CFD data, and come after two earlier tests this year. In January, a 2018 car of 60% scale was used while, in March, a different design of a 2021 car was wind tested with the upcoming 13 inch wheels.
While some of the elements of the design of this latest 2021 model are expected to be kept when the rules are formally announced later this season, the FIA says areas such as the front wing are likely to evolve.
The FIA have released an exclusive video showing the 2021 50% scale model tests, complete with a movable rake behind the car to measure the extent of the turbulence being thrown up by the car. This is so F1 and the FIA can then take this data into consideration as the rules are written to improve this.
“Typically teams would not use a rake in this position because teams don’t really care about the wake of the car,” explains FIA Head of Single Seater Technical Matters, Nikolas Tombazis. “That’s not a criticism; teams are simply trying to maximise the performance of their own car, which is completely understandable. We, however, are more interested in what happens behind the car. The fundamental point of all of this is that we are trying to reduce the losses that the following car would face.”
“The rake features an array of pitot tubes with yaw sensitivity, so they can measure the direction, pressure and the velocity of the flow, mainly the velocity components and the pressure,” added Tombazis. “In that way we can make sure that what the CFD is predicting is correct.
“The simplification of the leading car’s aerodynamics also helps for wake performance because on the one hand the front car doesn’t have as many methods to control its wake. On the other hand the following car, not having all these little, very sensitive devices is less susceptible to disruption.”
Pat Symonds, Chief Technical Officer at Formula 1 added that while the bulk of the development work taking place for the 2021 technical regulations has been conducted using CFD (Computation Fluid Dynamics) the wind tunnel tests offer a real-world validation of the modelling carried out in the virtual space. “While the CFD tools we are using feature some pretty advanced techniques which aren’t commonly used by the teams, we want to back up the virtual simulations with a physical simulation,” he says.
“We chose to use a 50% model rather than a 60% model and we chose to run that model quite a long way forward in the wind tunnel, so this gave us the opportunity to best inspect the wake of the car,” Symonds explained.
“It takes up less room in the tunnel and therefore it allows us to look, in terms of car lengths, further behind. If you imagine you have a full size car in there, you could only look at a tenth of a car when it is behind, so 50% is a good compromise in that we can still get a good level of detail on the model but we still have distance behind. It is true that teams have tended to go more to 60% these days. There are advantages to that, in modelling, but modern manufacturing techniques, particularly additive manufacturing methods, allow you to make very accurate 50% models these days.”
According to the FIA, the collected information has completely backed up the CFD data and shows a significantly reduced wake turbulence has been achieved with the 2021 regulations: “There have been no major surprises.” said Tombazis. “So there is a 5-10% wake disruption, compared to the current levels of 50%, although it depends on the exact configuration you are testing and so on.”
Symonds was similarly happy with the findings, saying the results are “actually beyond what I thought we could achieve when we started the project. With the configurations we have got at the moment, the results are exceptional.”
All information gathered by the FIA, Formula 1 and any parties involved in the CFD designs and wind tunnel testing is being shared with all other parties, to ensure that no team can gain an early advantage. This information sharing also extends to parties outside immediate involvement, such as some of the smaller, lesser-resourced F1 teams. They still receive all information that is collected, to ensure transparency ahead of the final rules announcement in October.