July 25, 2013
UPDATE: Endurance was the name of the game for a group of UT engineers last week as they persevered against sweltering three-digit temperatures and last-minute equipment failures to pull off sixth place at this year’s Formula Sun Grand Prix.
The University of Texas Solar Vehicles Team (UTSVT) took sixth place in the Formula Sun Grand Prix (FSGP) at the Circuit of the Americas track held June 24-29. FSGP teams raced on a 3.4 mile road style closed course over the three-day competition. TexSun completed a total of 121 laps; their fastest lap was clocked at 5:02.
The winner of FSGP 2013 was Oregon State with 193 laps. They were followed by Illinois State with 192 laps and Iowa State with 191 laps.
After two years of designing and constructing TexSun, the University of Texas at Austin Solar Vehicles Team (UTSVT) will debut their solar vehicle at the thirteenth annual Formula Sun Grand Prix (FSGP). This year’s race will take place at the Circuit of the Americas racetrack June 24-29. With a goal to win first place, Benton Greene, an aerospace engineering graduate student, hopes his two years of hard work and determination will pay off.
The TexSun will be competing in a race of endurance on a road style closed course. The winner of the FSGP is the team that completes the most total number of laps over a three-day period of racing, minus any penalties accumulated. The Formula Sun Grand Prix was created in 2000 to serve as a qualifier for teams interested in competing in the American Solar Challenge, a cross-country road race in North America that takes place every other summer.
Twelve teams from universities around the country and one from Canada are competing in this year’s race. Circuit of The Americas is sponsoring the UTSVT covering $50,000 of costs associated with building the TexSun vehicle.
Professor Gary Hallock of the Department of Electrical and Computer Engineering has led the team for over ten years. The TexSun is the third solar car he’s been involved with.
“The team has been working night and day finishing the car,” he said. “I am extremely proud of the students. Our entry will be very competitive and highlight what UT engineering students can accomplish.”
Greene joined the UTSVT in 2006. He was chosen in 2011 to be a team lead for the construction of TexSun. His main responsibility in this position is to ensure that the body of the vehicle is completed in time to compete in the FSGP.
“One of the biggest responsibilities of being a team lead is to get the body of the vehicle built in time for the race and to coordinate all the work associated with the body aspects of car,” Greene said. “But my biggest challenge during the last two years was constructing the body, because unexpected delays set us back on creating the foam plugs and the fiber glass molds.”
The solar vehicle was built around an aluminum space frame chassis, that supports a three wheel design and a body shell made out of carbon fiber. The two wheels in the front of the vehicle are for steering and the single wheel in the back is used for driving. The TexSun motor is 95 percent efficient, and dictates the amount of voltage needed from the battery pack. The battery pack – used for energy storage – will consist of 40 kilograms of Lithium Iron Phosphate batteries. The battery pack can only recharge by using solar energy captured by solar arrays. There are six square meters of solar arrays that sit on top of the carbon fiber body shell of TexSun. The solar cells are 22.5 percent efficient, meaning they can convert 22.5 percent of the sunlight that hits them into electricity.
“There’s not a lot of power to work with when it comes to solar vehicles, so that’s a big design challenge – where can you cut out power losses,” Greene said.
Greene is the only current member on the team with an aerospace background. The rest of the team is made up of mechanical and electrical engineers. His aerospace background has vastly contributed to how the car will work. Greene believes it is important to design a streamlined car that is also very smooth.
“Aerodynamics is really important when it comes to building the body of the solar vehicle and that’s where my expertise comes in,” Greene said. “I have to make TexSun as aerodynamic as possible because the atmosphere is in its way and it takes a lot of power to push the air out of the way.”
Greene is currently working on his master’s degree in aerospace engineering with faculty advisor Professor Noel Clemens. The two are working on a project for the U.S. Air Force to control shock boundary layer interaction with pulsed plasma jets. Greene is studying the effect of pulsed plasma jet actuators on flow separation and flow distortion that can occur in supersonic inlets when a vehicle is traveling at supersonic speed.
“Being on the solar vehicle team has given me management skills I can use when I go out onto the field,” Greene said. “I now have experience on people management, project management and really good experience in designing and building, which is what a lot of engineering is.”
After completing his master’s and doctorate degrees, Greene plans to work in the space industry.
