AMES, Iowa – Team PrISUm’s latest solar race car is already ahead of the last one.
Over the past week, the team has taken Hyperion, this year’s cross-country race car, out for several test runs, including a trip to Grinnell.
That long test run was huge for the student-engineers working on their $330,000 project. That test drive told the students their aerodynamic ideas are making a difference, that their target speed should be about 45 mph and that they still need to do some tweaking to get the most out of their car.
Two years ago, when student-designed and student-built solar-powered cars raced from Broken Arrow, Okla., to Naperville, Ill., Iowa State students weren't able to do much pre-race testing of the car they named Anthelion. One consequence was persistent electrical problems that slowed the car to an 11th-place finish.
Now, already, “we’ve had a fairly successful run,” said Evan Stumpges, the team’s project director. “It’s nice to have some miles in Ames before we head out.”
The team’s first stop on its race calendar is the Formula Sun Grand Prix at the Monticello Motor Club in Monticello, N.Y. The team will be there July 6-12 to go through technical inspections and try to turn enough laps to qualify for the cross-country American Solar Challenge.
The July 14-21 challenge will take solar car teams 1,650 miles from Rochester, N.Y., to St. Paul, Minn. Team PrISUm is one of 18 teams registered for the race.
Team members said the early testing has been encouraging.
“I feel pretty optimistic right now,” said Stumpges, a May mechanical engineering graduate from Pauma Valley, Calif., and a future engineer for Caterpillar Inc. in Peoria, Ill. “Honestly, over the four years I’ve been involved with the team, this is the most prepared we’ve ever been heading into a competition.”
The team, for example, already knows some of this year’s design innovations are making a difference.
Zach Noel, a junior from Denison who’s studying aerospace engineering, worked on redesigning the solar car’s aerodynamics. This year’s car has a sleek canopy with a short shark fin at the back. (The last car’s canopy was more of a bubble than a streamlined aerodynamic component.)
Noel said computer simulations predicted Hyperion would slice through the air significantly better than Anthelion. But there’s nothing like road miles to confirm the new design really does work.
Jonathan Bauer, a senior from Camas, Wash., who’s studying mechanical engineering, explained how changes to the suspension make it much easier – and faster – to make wheel changes during pit stops. He also detailed how other changes allowed the team to reduce the bulk of the suspension A-arms and trim some weight from the car.
In all, Stumpges said the new car is 50 pounds lighter than the old car. That can make a big difference when you’re running on sunshine and a small electric motor.
There’s still work to do – earlier this week a parking brake needed to be built and installed – but the team is feeling good about its chances on the road.
“We’re sticking to the game plan,” Stumpges said. “And so far, Hyperion is working as designed and holding up well.”