"Carting" a course to learning

Students on race their carts using a pressurized water tank as propellantAt first mention, Introduction to Fluid Mechanics might not sound like a whole lot of fun. In the required course for civil and environmental engineering majors, undergraduates solve differential equations and strive to grasp complex concepts about how velocity, pressure, density and temperature affect liquids and gases over space and time.

But Professor Brett Sanders, who teaches CEE 170, is determined to make learning fun while imbuing some practical experience in his undergrads. For the fourth consecutive year, his curriculum includes a mandatory – and very hands-on – cart race. Students form teams to design, fabricate and race hand-made vehicles propelled by a pressurized water tank. The carts, built on a skateboard foundation, must traverse a 50-foot course with a 2 percent incline, and teams compete in two categories: speed and accuracy.

The undergraduates are responsible not only for design, but for acquiring material to build their carts. Sanders notes that this has inspired an outpouring of creativity; he’s seen “everything from trash bins to mixing bowls.”

Students can build their carts in an Engineering Tower fabrication lab that includes saws, drills, sanders and other hand tools, but not before participating in a one-hour safety-training session to learn proper usage. For student Carina Dan, that went a long way toward helping her conquer her fear of power tools. “The training did give me confidence. Knowing the right way to operate the tools was an important step for me.”

Fabrication is just one aspect of the assignment. Teams are also responsible for determining optimum settings for the water tank’s nozzle diameter, jet angle, pounds per square inch of pressure, and water height. A couple of weeks before the final race, they test their vehicles in a 10-minute trial run, then use the test data to fine-tune their designs. Additionally, students are tasked with trying to predict their race-day times using a Matlab program that incorporates specific parameters like water pressure, water height and nozzle size.

“Fluid mechanics includes some topics that can seem counter-intuitive and it involves the application of advanced mathematics, so it’s easy for students to feel overwhelmed,” Sanders says. “Having a project where [they] see the application of concepts makes comprehension a lot easier.”

Not to mention more fun. On race day, laughter, good sportsmanship and team spirit seem to override the damp clothing, sometimes disappointing race times and occasional vehicle wipeouts.

“The cart race was a lot of fun,” says student Ronald Domholdt. “In particular, I loved simulating the cart runs and extracting parameters from the data gathered.”

Domholdt adds that as his team’s project manager, he also gained experience in managing the group’s output and performance. “I learned how to hold myself and others accountable, and in the future I feel it will help me improve in my dealings with others.”

Teams are also responsible for determining optimum settings for the water tank’s nozzle diameter, jet angle, pounds per square inch of pressure, and water height.Wade Monsen, who took CEE 170 as an undergraduate and now serves as the class TA who oversees the fabrication lab, believes the experience is an effective learning tool. “After the testing session with the pressure tank, most teams realize why their cart was unstable or how it could be improved, and then attempt to correct those issues before the final race,” he says. “Testing their own design allows each team to learn from their mistakes … this emphasizes some of the course content.”

He adds that the rewards of working with a team make students more likely to learn in the process. “I think students retain more information when they enjoy what they are doing.”

Carina Dan agrees. “I chose engineering because I enjoy putting things in practice – applied math rather than abstract problems,” she says. “So I will always value the opportunity of hands-on projects, and I always retain more information when practically applying the concepts.”

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