Digital design has become central to Formula 1 racing, but don’t rule out wind tunnels just yet. That is the message coming out of a recent F1 Strategy Group meeting. The group comprises the sport’s governing body FIA, the sport’s commercial arm run by Bernie Ecclestone and the top six teams.
The stakeholders responsible for some of the fastest cars in the world are considering a move that would prohibit wind tunnel testing, but their proposal has been met with resistance from team leaders and fans alike, who don’t think CFD technology is mature enough to obviate real-world wind tunnel testing just yet. Leaders from Ferrari, Mercedes and Williams were especially skeptical of the ban, while McLaren, Red Bull and Force India have expressed varying degrees of support.
F1 teams typically begin the design and testing process with computational fluid dynamics (CFD) since it allows them to experiment with many design variables in a short time frame without having to build anything. The second step is to build a physical scale model of the car and put it in a wind tunnel, enabling teams to conduct further testing, including evaluating the car’s aerodynamic efficiency. Once the car is constructed, then comes the track testing.
The fact is, though, that real world track testing, wind tunnel testing and CFD simulation work are all heavily restricted by the sport’s governing body. In 2015, a team’s allotted wind tunnel time dropped from 80 hours per week to 65 hours per week with wind-on hours reduced from 30 hours per week to 25 hours. Computational fluid dynamics (CFD) usage was reduced from 30 teraflops to 25 teraflops per week. Track testing has also been curtailed; pre-season testing has gone from three to two sessions and in-season testing is set to be cut altogether. These changes were enacted as cost-saving measures, but some feel they are holding back the sport.
“It appears this teraflop restriction has pushed the engineers, as usual, to go to the limit of the regulations and we basically had to use some old chips,” said McLaren racing director Eric Boullier as reported by Autosport. “The consequence of this is we are not using the latest technology in terms of computing.
“We don’t think it’s good for Formula One to use ten-year-old technology — we are supposed to be at the top. Some discussions have taken place about changing the regulation from this teraflop story to an energy bandwidth control. This would allow more freedom for the teams to do what they want with their computers, but still being regulated, the same with the FIA. That’s something we are very much in favour of, because it would be right for F1.
“Then on the windtunnels if you allow the CFD development maybe one day windtunnels could be obsolete. We would be happy to implement [the new technology] as soon as possible.”
It’s generally agreed upon that virtual wind tunnels are not as accurate as either real world or wind tunnel testing. But it is quicker and cheaper in that many different designs can be processed in a short time without actually having to manufacturer all of those parts. The combination of CFD, wind tunnel and track testing enables teams to maximize efficiency, but are the limitations hampering progress? Are they making the sport less exiting? And what about the cost factor?
“We’ve actually done a deep analysis of the costs involved in running our tunnel and how much it would actually save if we closed it and the numbers correlate with the numbers that are currently in circulation at the moment,” said Williams deputy team principal Claire Williams. “It is minimal, the amount that you would save. Again, the compensatory elements… you would just save that money elsewhere as F1 teams, any cash that you would save somewhere, you would go and spend somewhere else.”
“We absolutely do not and will never vote for the banning of windtunnels in Formula 1,” said Williams, whose team has two tunnels. “How can you operate at the pinnacle of motorsport and not use one of the finest tools in aerodynamics? It doesn’t make any sense to us.”
Mercedes chief Toto Wolff added: “A windtunnel is needed today to put a car on the street, verify what’s being done in CFD and get correlation.”
As for the fans, opinions are all over the place. Some are eager to see the aeronautics advances that they believe would come from fewer restrictions on CFD and wind tunnels. Others think the sport is more interesting with a level playing field that gives low-budget teams a shot at being competitive.
There is also a compelling technology argument to be made for putting the force of the F1 into CFD.
Says one racing afficianado, Javier: “I believe a formula relying entirely on CFD could be exciting; a chance to see what aero engineering might look like in 10 or 20 years. F1 keeps talking up the importance of technology transfer, which is why they introduced hybrid power units. If they want to be serious, a move to pure CFD would be an excellent choice.”