Propane Vehicle Challenge
Engineering students submit their propane-powered minivan and truck designs to laboratory and road tests as well as design judging as part of international competition
Seventeen student engineering teams from universities in the United States, Canada, and Puerto Rico brought their modified vehicles to Southwest Research Institute (SwRI) in May for the 1997 Propane Vehicle Challenge (PVC).
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The SwRI Department of Emissions Research gave 17 university student engineering teams a unique opportunity to run their test vehicles on SwRI's Horiba electric chassis dynamometer under the same test procedure used to certify new vehicles. The 42-minute test simulates both stop-and-go and freeway driving. |
Team vehicles, which were redesigned minivans and compact trucks donated for the competition, underwent emissions testing, cold- and hot-start testing, design evaluation, and dynamic events including range and fuel economy tests, a quarter-mile acceleration test, and a vehicle handling evaluation.
SwRI sponsored the second annual international student engineering competition along with the U.S. Department of Energy, Railroad Commission of Texas, Chrysler Corporation, Texas State Energy Conservation Office, Argonne National Laboratory, and Natural Resources Canada.
The competition started at SwRI's emissions laboratory. Emissions tests followed federal test procedures used to certify new vehicles and were run on a Horiba electric chassis dynamometer through stop-and-go and freeway simulations.
Kevin Whitney, a research engineer in the Automotive Products and Emissions Research Division and an SwRI PVC organizer, said many of the component designs were on the cutting edge of technology.
"One of the more interesting components I saw in the Challenge was the conformable fuel storage tank used by a number of the minivan teams. This compact design fits where the standard gasoline tank is usually located and allows a large amount of fuel to be stored in a single tank rather than many tanks manifolded together," Whitney said. "A number of the liquid-injection systems were also very promising. I think these types of systems will be necessary to meet customer demand for power and fuel economy while still meeting stringent new exhaust emissions standards."
Simplicity and experience won out in emissions testing. Charles Hare, director of the Emissions Research Department, awarded prizes for lowest emissions to Texas Tech University's minivan team and the truck team from the University of Waterloo.
"We tried to keep our design simple," said Bill Moreau, team leader for first-year competitor University of Waterloo, Ontario. "We wanted to make our design as if this truck could easily be converted in a local conversion shop."
Waterloo's vehicle emissions testing showed 0.07 grams per mile (g/mi) of hydrocarbons, 2.62 g/mi of carbon monoxide, and 0.24 g/mi of oxides of nitrogen.
Texas Tech, in its second year of competition, met the 1997 California Ultra Low Emissions Vehicle (ULEV) standards with its minivan for emissions of carbon monoxide (0.51 g/mi) and oxides of nitrogen (0.32 g/mi). Its hydrocarbon emissions measured 0.067 g/mi, just short of the 0.05 g/mi required under California ULEV.
"Emissions tests were the most heavily weighted test category in the competition," Whitney said. "Of a possible final total of 1,000 points, 200 were awarded for emissions and another 100 for fuel economy tests. This is because part of the competition's purpose is to demonstrate the clean-burning, fuel-efficient qualities of propane. We knew there would be a close relationship between the final emissions scores and the choice of fuel delivery system, but the interdependency was stronger than we had expected."
While 10 teams chose liquid fuel injection, five opted for gaseous fuel injection, and two chose gaseous carburetion systems.
Waterloo used a multi-port vapor injection system, and Texas Tech utilized a multi-port gaseous injection system.
After emissions testing, each team gave an oral presentation to a panel of judges explaining how they had modified their vehicle. Texas Tech and Waterloo also earned first place in the oral presentation portion for their respective categories.
"It is interesting to see that for months you thought you had the best design, but when you get here, you realize there are many different concepts and solutions," said Texas Tech Team Leader Richard Howlett.
Vehicles also were tested for cold-start and hot-start at Northside Independent School District's transportation facility in San Antonio. After the vehicles cooled for 13 hours, they were connected to a Diagnostic Scan Tool Data Link Connector and the number of engine power pulses from the crankshaft sensor were measured and recorded for the cold-start measurements. After five to 20 minutes, teams started their vehicles for the hot-start test.
Following design judging and opening ceremonies at Sea World of Texas, teams and organizers caravaned to College Station, Texas, to compete in dynamic events at the Texas World Speedway. Vehicles underwent tests measuring range and fuel economy, as well as quarter-mile acceleration. The timed handling test required students to maneuver their vehicle quickly through a slalom course, then change drivers and repeat the course, without knocking over a pylon or driving off the track.
The PVC closed at the University of Texas at Austin with an awards ceremony to honor the winning teams. Minivan teams were in their second year of competition, while the truck category was new to the Challenge.
General Motors Engineering and Management Institute (minivan) and the University of Waterloo (truck) were awarded first place overall. Texas Tech University received second place overall in the minivan category, and Texas A&M University was awarded second place overall in the truck category. Third place overall awards went to the University of Texas at El Paso (minivan) and the University of Tennessee at Knoxville (truck). Canadians also claimed fourth place overall with The University of Alberta (minivan) and University of Windsor (truck) taking the trophies. Students from Western Washington University got the fifth place overall award for minivans, while Virginia Tech claimed fifth place for its truck.
Other schools that participated in the minivan category included Cedarville College in Ohio, École de Technologie Supérieure in Quebec, Illinois Institute of Technology, and the University of Texas at Austin. Other truck teams included the University of California at Riverside, the University of Kansas, and the University of Puerto Rico at Mayagüez.
Published in the Fall 1997 issue of Technology Today®, published by Southwest Research Institute. For more information, contact Joe Fohn.
