In what might be a growing trend for less well-funded teams on the grid, the technical team of Virgin Racing, headed by Nick Wirth, has relied exclusively on Computational Fluid Dynamics (CFD) for the aerodynamic design of their new VR-01. In so doing, they have eschewed what has now become a standard tool in aero design, namely, the wind tunnel.
Nick Wirth, who has relied on CFD for other formulas, e.g. ALMS prototypes, has touted this simulation technique as an economic alternative for the future. Some of his rival technical heads are not so sure, however.
Mike Gasoyne, the new tech head at Lotus, for example, recently expressed his reservations, as reported on ESPNF1. “I think [CFD] is an integral part [of aerodynamic design],” he said, “but it is not a complete part.”
By way of illustration, Gascoyne cited two examples of teams who had made substantial investments in sophisticated CFD programs, yet still relied on wind tunnel testing to augment their data. “You look at BMW when Albert II was announced as one of the world’s biggest supercomputers dedicated just to their CFD,” Gascoyne said. “If you look at Enstone, they built their environmentally-friendly CFD centre with a huge computing resource. I don’t think these guys are idiots, and they also have wind tunnels.”
Adrian Newey, technical director of Red Bull, and a superb aerodynamicist in his own right, echoes Gascoyne’s seintiments. “I think CFD is a very powerful tool, there is no doubt about it,” Newey said. “It is another way of simulating the real environment. A wind tunnel is [also] a simulation of the real world.”
One meaasure of the difference between the two forms of simulation is the volume of data than can be collected within a given time frame. According to Newey, “Every single run in CFD for a given attitude of the car, or ride height, or whatever it might be, is a discreet run. Whereas in the wind tunnel, what we call a normal run, will have 20 or more data points in it. In other words, that is equivalent to 20 runs in the CFD. That is a limitation of size really, so your CFD cluster has to be that much bigger to do that many runs. And there are some areas that CFD physically doesn’t capture as well as a wind tunnel – like basic aerodynamic properties.”
Yet, Newey, like any decent designer, is willing to keep an open mind. He knows that ultimately the value of any given method of design will be substantiated by performance. “So how well it turns out, we shall see,” Newey said. “It is a different route, and my personal belief is that you still need to combine the two at the moment. But maybe their car will go very well and I will have to revise my opinion.”
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