INSIGHT: F1 WIND TUNNEL TECHNOLOGY REACHES AMAZING NEW LEVELS OF INNOVATION
POSTED BY: JAMES ALLEN, 12 FEB 2018
Here at JA on F1 we like to take readers’ questions direct to people who know the answer. That’s how the original FOTA Fans Forum started in 2010.
We had this question about the level of sophistication of F1 wind tunnels and we put it to Professor Mark Gillan, formerly chief operations engineer at Toyota and Williams in F1 and a leading expert on wind tunnel development.
His answer shows how amazing the level of technology has become – with teams even able to introduce exhaust flows into the testing model – but also raises questions about how there is this whole side to the sport which is hidden away and secret.
Question: What do you know about or have heard about centrifugal forces research in F1? What, if any, differences are there between a stationary wind tunnel model, A rolling road wind tunnel model, and a engine running wheels turning wind tunnel model/actual car.
Hell, it keeps bikes running upright as if they have a ghost rider. There’s a strong force there. It has at least been looked at? Is there any exploitation of it in F1?
Prof Mark Gillan’s answer: Recent developments over the last decade in motorsport wind tunnel testing have been transformative.
However it should be noted that some of what goes on within an F1 tunnel facility is somewhat artificially directed by the restrictions in facility usage (via the F1 regulations), especially with regards to model size (now at 60% max scale in F1 through regulation), speed, wind on time, number of runs and tunnel occupancy.
During the last decade there has been a dramatic push in the following areas:
i) Aggressive application of enhanced efficient wind tunnel testing methodologies, including continuous motion systems, high speed data acquisition analysis, with ultra-quick model changes;
ii) Shape, aeroelasticity and turbulence intensity matching of model scale to full scale;
iii) True cornering studies with proper interference correction methodologies;
iv) Steel belt rolling road systems with eccentric wheel drive units for tracking tyre contact patch movement and measuring wheel lift through the belt;
v) Real time robotic flow visualisation and automatic minimal interference full flow field interrogation;
vi) Remote health monitoring of facility and Key Performance Indicators (or KPIs) tracking tools.
So to specifically answer your reader’s question; over the last decade the wind tunnel model testing process has transitioned from fixed steady state single ride height, yaw and steer systems to fully dynamic continuous motion models, integrated with high speed balances, pressure sensors and acquisition systems that map the entire operating envelope of the car within a few minutes of wind on time.
Typically this sweep is done with a roof-mounted hexapod system.
The rolling road systems and integrated boundary layer bleed systems not only give a more realistic flow field around the car – particularly in the diffuser region – but also allows you to measure wheel-lift through the belt using the eccentric wheel pads that sit underneath the tyre contact patches.
The teams can also run pseudo exhaust flows using integrated pneumatic systems or on board high speed electric motors.
There are even attempts to represent cornering manoeuvres, but this activity and process is secret.
As the teams drive their continuous motion systems faster and faster they do come up against limits and inertial effects play into this.
The teams then feed these complex multi-dimensional aero maps (measured in the tunnel) into their driver in the loop simulators.
The simulators help the teams better understand the importance of transient effects and stability criteria though performing “what if” studies.
These studies help drive the weighting criteria and KPIs in the tunnel and pinpoint what the test programme should include.
With each week F1 wind tunnel testing becomes more advanced, more dynamic and more realistic, with continuous improved correlation between CFD, the tunnel and the track.