One Man's Fluid Dynamics Is Another Man's NASCAR Race

I admit it. I don't get NASCAR. A lot of people do, of course, but not me. For that matter, I don't get golf either. Curling -- the type you play on ice, not in a hair salon -- I get. Fluid dynamics I get. But cars going in circles?

Luckily, enough people do get NASCAR enough to make it worthwhile for researchers to learn more about it. Which is what Zoran Popovic, an associate professor in the University of Washington's Computer Science department, has done. Along with Adrien Treuille and Andrew Lewis, Popovic has developed software that lets television viewers see how air flows around speeding cars. Applying what most Dr. Dobb's readers know as "real-time fluid dynamics simulations," Popovic's application calculates air flow over the cars, then displays it as colors trailing behind the car. Green, blue, yellow, and red correspond to different speeds and directions for air flow when two or more cars approach one another at speeds of 200 miles per hour.

The problem Popovic took on was to figure out how to simulate and display complex systems in real-time very quickly, and on standard (not high performance) computers. To make the simulation work in real time and be interactive, "you kind of need to rethink the math problem," Popovic says. "The method that ended up being used is drastically different from what people have done before."

The new algorithm first simulates all the ways that NASCAR cars behave. Then it runs the simulation for a reduced number of physically possible parameters. This lets the model run a million times faster than before. (For details, see their paper Model Reduction for Real-time Fluids.)

"What's interesting is how the flow from the car in front is affecting the cars behind," says Popovic. "When there are two cars behind, then the interaction becomes very complex."

An company called Sportvision, which creates technology to enhance sports coverage, has signed a nonexclusive, open-source license to the technology. Okay, I might tune in a NASCAR race just to see real-time fluid dynamics in action. But what I'm really waiting for is to see how it works in curling.

Posted by Jon Erickson at 03:46 PM  Permalink