Missouri S&T students simulated airflow around the #92 car to gain optimum downforce in specific areas without inflicting detrimental effects on other parts of the car. This image is an isometric view showing static pressure contours on the surface with pathlines colored by velocity. | What happens when you marry high-performance formula-style racing with high performance computing (HPC)? A group of students from Missouri University of Science and Technology (Missouri S&T) have discovered that this winning combination yields both powerful results and outstanding opportunities. For the past 21 years, Missouri S&T’s Formula SAE racing team, part of the university’s Student Design and Experiential Learning Center (SDELC), has set its sights on a first-place finish in the Formula Society of Automotive Engineers (SAE) collegiate competition that challenges engineering students to build and compete with a formula-style race car against teams from around the world. The event is designed to simulate a real-life scenario where a “corporation” commissions a group of engineers to design and build a prototype car. Annual competitions are held worldwide, including U.S. races at Michigan International Speedway, Virginia International Raceway, and California Speedway. Each year, more than 300 teams take part in the two-phase competition that includes a series of static events, including cost analysis, sales presentation, and engineering design, as well as dynamic events like acceleration, skid pad testing, and both autocross and endurance races. Static events are judged by marketing and product development specialists at the Big 3 automotive companies: Ford, General Motors, and Daimler-Chrysler. For students like senior Andrew D’Hooge, a double major in mechanical and aerospace engineering, being part of the Missouri S&T racing team is more than an extracurricular activity. It’s an integral part of the curriculum, an opportunity to reinforce classroom lessons with hands-on design and build tasks in an environment that fosters teamwork, leadership, and communication—essential skills in the engineering field. Aerodynamics: A Novel Approach
As the aerodynamics group leader, D’Hooge is responsible for designing and testing all aero components on the Missouri S&T #92 car, with an eye toward the ultimate goal of achieving maximum downforce with minimal mass. “We’re one of only a handful of teams that consistently run an aerodynamics package,” D’Hooge says. In a sport where the average course speed is around 35 mph and speeds in excess of 60 mph are a rarity, reducing drag isn’t as much of a concern as is optimizing downforce. “Since there aren’t a lot of straight-aways in Formula SAE, cornering is a major component. The more downforce you can generate, the better handling and lateral maneuvering capability you can achieve.” But generating this valuable downforce must be accomplished with precision and without added weight. Generating downforce is one thing, but generating it where it can do the most good is vital—too much in one area of the car can impact maneuverability. And, the weight of added components can overwhelm the aero benefits. Achieving Optimum Design through CFD
To achieve the optimum design and analyze the aero impact on the overall performance of the car, D’Hooge and his teammates are using cutting-edge computational fluid dynamics (CFD) and extreme visualization software to perfect the design conceptually, before any manufacturing ever takes place. Because the group must essentially start from scratch to build a new car each year, the CFD approach significantly reduces build time and eliminates physical trial and error. “The goal with implementing CFD in the design process is to reduce manufacturing time to allow for more testing time,” D’Hooge says. “Once we’ve arrived at a final design with the CFD, we can then validate the results in a wind tunnel. Ensuring reliability of the components is equally important. No matter how they impact the performance of the car, we have to be sure they will stand up to the rigors of the competition.” D’Hooge and his team begin the process the same as any other team, with concept generation, brainstorming, and discussion of implementation plans. Once the concept for an individual component is established, like the front wing for example, a CAD image is rendered using Siemens PLM Software’s NX 5 CAD/CAM/CAE software. From this image, team members then turn to Fluent’s GAMBIT 2.2 to generate the million-plus component finite mesh. The mesh is then imported into Fluent 6.3 for flow modeling. Extreme Visualization/ Quick Results
To visualize the model, the team uses EnSight extreme visualization software by CEI, Inc. of Apex, NC. EnSight allows the team to quickly and accurately preview the results of possible design iterations before any changes are made on the shop floor. “We had been doing our postprocessing work in Fluent, but EnSight has proven to be far easier to use and offers far more expanded capabilities,” D’Hooge says. “Thanks to the CFD and the ability to visualize the components before we make them, we can now turn around parts in a day, from the initial concept through drawing, meshing, and postprocessing.” The ability to visualize the results of design changes is a critical time-saver for the Missouri S&T team. With no on-site access to a full-scale wind tunnel to test their components, the team must be well-prepared for its annual Spring Break visit to the Ford Motor Company wind tunnel in Detroit. This, the final step in the build process, is an opportunity for the team to validate its results by correlating CFD data with real data gleaned from the wind tunnel tests. “Once we’ve validated the CFD results in the wind tunnel, we can then use this data as a broader design tool,” D’Hooge says. Even though at this point in the process there is no time left to redesign components before the first competition, the data still has incredible value for the team. While they do have to start the build from scratch next year, they can use the same design elements and CFD models in an evolutionary design strategy, again saving the team precious time in development. With EnSight on their team, the Missouri S&T students have definitely found a competitive advantage both on and off the track. EnSight’s flexibility and ease of use have made design alterations quick and effective. “EnSight’s interface is really easy to use and it’s very intuitive,” D’Hooge says. “We can jump right into using it without having to sit down and read a manual. It gives us the ability to iterate individual components through numerous designs, and even incorporate these analyses into a full-car CFD, to see how each component affects the whole car before we even start to build.” Selling the Science
In addition to providing the pre-build analysis that is critical to the car’s performance in the dynamic events, the images and animations generated in EnSight are used as part of the marketing presentation portion of the competition and for promotional materials to gather sponsors for the team. Performance benefits aside, D’Hooge says one of the greatest advantages of using cutting-edge tools like EnSight is the opportunity to gain valuable experience with industry-standard software and design procedures, just like it’s done in the real world. “A lot of former members have had some excellent job opportunities as a result of being part of the team, with OEMs, the Big 3, and we even have several alumni in the motorsports industry,” he says. “It’s a valuable experience to have the opportunity to learn how to use these tools, but the team aspect is also a major benefit. These are skills you can’t teach in a classroom. But here we get hands-on experience using the same software and manufacturing processes as the Formula One teams are using.” The 2009 Missouri S&T team is looking to build upon its previous three top 10 finishes in the past six seasons and is set to compete in three domestic competitions this season at the Virginia International Raceway, at Michigan International Speedway, and at California Speedway. More Info
ANSYS, Inc./Fluent
Canonsburg, PA CEI, Inc.
Apex, NC Siemens PLM Software
Plano, TX Missouri S&T Formula SAE Racing Formula SAE Collegiate Design Series
Kara L. Gray is a professional writing and public relations consultant specializing in technology, manufacturing, and non-profit communications. You can send an e-mail about this article to DE-Editors@deskeng.com.
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