A new term is being introduced in Formula 1 aerodynamics, one of the most important things to be taken into consideration when designing an F1 racing car. “Transient Aerodynamics”, which describes the way a modern racing car behaves while turning.
It is a part of aerodynamics that is being neglected, at least by the smaller F1 teams. The basic principles of modern aerodynamics are being determined by testing the racing car on straight road. The target there is to get the maximum aerodynamic load with the least possible resistance, thus attaining the best aerodynamic efficiency (load / resistance ratio).
Many aerodynamics engineers believe, or want to believe that if their racing car can get the required load, then this is going to be good enough while turning also. In other words they believe that if they achieve a satisfactory amount of load, then “problems” like transient aerodynamics are being solved automoatically.
The other part of the story
“No driver has ever complained to me about the way the car behaves on the straight. They always complain about turns.”
This is what Gary Anderson, designer for team Jordan and Jaguar for years, told a reporter. And he continues: “But there it is. The best part of aerodynamic testing is taking place while straightline running. I have seen racing cars being transmuted from a car its driver hates to a car he loves, just by interfering with transient aerodynamics. Some times with the cost of losing several kp of load, but with great lap time gains.”
What happens in aerodynamic tunnels?
Anderson is right. Either inside aerodynamic tunnels or long straights testing, straightline aerodynamics are consuming the best part of the working days. Only the last decade the aerodynamic tunnels have gained the ability to simulate turns. The way each team will work depends on the scientific “school” its head aerodynamic engineer belongs to.
What about Bridgestone?
With the new Bridgestone tyres (common for all the teams – 4 types – hard, medium, soft, super soft), transient aerodynamics section has become even more determining. No matter what tyres you are using, when you have a racing downforce generating car, you have to make the aerodynamics work with that particular tyres.
“Michelin had been “edgy”. Their efficiency has been high and the driver could easily understand where the limit was. They where optimized to work under a small “slip angle”, around 2%-3%.
New Bridgestone tyres feel more stable and work smoothly without changing behaviour for a longer time. They may even have to offer more grip, but the driver can’t take advantage of it as the feedback he gets is poor. Also the “slip angle” is reaching 5% - 6%. In other words you can turn more without slipping.”
“It is essential not to lose your aerodynamic efficiency when the tyre is at its peak. You need maximum aerodynamic efficiency when your tyres give their maximum. You have to have aerodynamic characteristics that fit the “real life”. So with this year’s Bridgestones you have to find a way to keep the aerodynamic load when the car is turning, when the air flow drops. You also have to take “pitch” and “roll” under consideration.
Simply you have to simulate and test all “real life” conditions, rather than having your racing car parked inside an aerodynamic tunnel, prepared for straightline racing.
