Meet the BAT 600, UW-Madison’s next clean snowmobile
After a team of UW-Madison College of Engineering students won the 2013 SAE Clean Snowmobile Challenge, members didn’t waste much time in taking a hard look at their work.
“Usually the week after competition, we come up with a list of things we want to do better,” says team leader and mechanical engineering senior Mike Solger.
In the competition’s 15-year history, the UW-Madison team has won five times. The competition’s overall goal is to develop vehicles for use in environmentally sensitive areas. And every year, the competition’s judges throw new engineering challenges at contestants, pushing them to create snowmobiles that aren’t just environmentally friendly but also quieter, faster, more reliable, and more resourceful.
For the 2014 competition, in early March at Michigan Technological University in Houghton, Mich., the team is modifying last year’s sled to improve its cams, belt-drive system, and exhaust system. (Teams have the option of updating the previous year’s snowmobile or starting with a new one, though all entries must be less than five years old.)
As is customary, the vehicle is also getting a new name to reflect its engineering ambitions. “The snowmobile will be the BAT, which stands for Bucky Ace Turbo—‘Ace’ referring to the engine that we use and ‘Turbo’ because we've added a turbocharger,” says team vice president and ME junior Jennifer Bartaszewicz.
Additionally, competitors must use a different fuel each year. This time around, it’s isobutanol, a biofuel generally derived from corn stalks, which comes with both advantages and unknowns.
“Isobutanol is a lot easier to work with than ethanol, because ethanol can be harsh on the engine,” Bartaszewicz says. “But, because isobutanol isn’t widely used in industry, there isn’t a whole lot of data to work with, and we’ve had to do a lot of our own testing.”
A California company, Web Cam, is making custom cams for the 2014 sled, in order to give its engine a lower dynamic compression ratio and to better use the turbocharger and take full advantage of economy and performance operating modes. To accommodate the new cams, the team also has to optimize the exhaust and intake systems and recalibrate its student-written engine control code.
This is where the UW-Madison Engine Research Center’s wealth of computing resources come into play. Graduate student Jeff Blair has helped the team develop a computer model of the engine, giving the students a leg up in predicting how their modifications will translate in real-life performance.
Having both joined the team as freshmen, Bartaszewicz and Solger dedicate a lot of time to mentoring and managing younger members. “We try to give everybody a project and not just let them stand around,” Bartaszewicz says. “We teach everybody how to weld and how to machine, which I found very beneficial when I was younger.”
The team’s repeated success is even more impressive in light of the relatively short amount of time members have to develop each year’s snowmobile. Their work doesn’t begin in earnest until the beginning of the preceding fall semester, when they recruit new team members. Even with the support of responsive sponsors and Mechanical Engineering Faculty Associate Glenn Bower, the months leading up to competition always prove hectic.
“We’ll sometimes be in the shop until midnight or 2 a.m.,” Bartaszewicz says. “During my freshman year, we slept in the shop for three days.”