U of M Solar Car sets new average speed record in Sunrayce 95
St. Francis, Kansas -- The University of Minnesota's solar-powered race car, the Aurora II, remains one of the top five vehicles in Sunrayce 95, a 1,150-mile solar-car race from Indianapolis to Golden, Col. The race began June 20 and ends June 29.
Aurora II began the race in fifth position after competing for one of 40 spots. Thirty-eight schools qualified for Sunrayce 95, and 36 remain after the University of Michigan withdrew last Friday, and University of Quebec on Monday.
The University of Minnesota moved into second position last Friday. After a full day of rain Sunday, the team dropped but was able to make a come back on Monday into 2nd place.
"The car has been performing as well as we expected," said Scott Grabow, Graduate Advisor. "We had a few minor problems in the beginning that we were able to overcome rather quickly. Now we just need to maintain a competitive strategy, which means we have to stay in tune with the weather and run the car accordingly. This may mean not running it full bore in the rain or consider running faster to move through a cloudy spot."
On Tuesday, June 27 Aurora II set a new Sunrayce record in which the Aurora II averaged 50.46 miles per hour over a 160 mile course. This is quite an accomplishment for a vehicle built by university students considering that Honda's Dream solar car averaged 55 miles per hour during one day of the the 1993 World Solar Challenge in Australia and did not have to worry about going through towns with 40 mile per hour speed limits, stop signs, and stop lights.
The Aurora II's aerodynamic shape and light-weight design are major contributing factors to the team's current standing. "We utilized EDS's (Electronic Data Systems) services to perform Computational Fluid Dynamic(CFD) analysis of Aurora II," said Grabow. "This data provided detailed information which was used to refine our design concept. Aurora II is the end result of 10 different vehicle design iterations."
The purpose of the CFD testing is to determine aerodynamic air flow and how it changes with each design iteration. Additional variables were factored into the analysis, such as road surfaces and varying weather conditions. The result is a vehicle that is aerodynamically stable, has low overall drag and is low to the ground, minimizing ground effect.
Grabow said, "EDS's assistance was invaluable to us. While we provided EDS with computer data for CFD analysis, we provided the same data to our student robotics expert to ensure the design was manufacturable before we got too far along in the design and development process. "Surfware's software product Surfcam played an important part in making sure the outer body design was manufacturable, according to Grabow. "This process saved us a lot of time and potential trouble in the CNC machining of our composite molds. These molds were the end result of EDS's CFD analysis and our preparation with Surfcam to make sure Aurora II's body was indeed manufacturable." The team's attention to detail is paying off, which is proven by Aurora II's performance, as well as by the Best Aerodynamic Shape award EDS presented to the team at the beginning of the race.