The world of NASCAR is fast-paced and unforgiving, where fractions of a second can make the difference between victory and defeat. In 2022, NASCAR introduced the NextGen race car, a major platform update designed to push the boundaries of performance and technology. However, with such a significant overhaul came challenges, including heat management for the driver’s comfort and endurance.
The shift to a closed flat floor design, which replaced the previous open undercarriage, restricted airflow under the car, resulting in excessive cabin heat. This posed comfort issues, with cockpit temperatures climbing to levels that could impact driver performance and endurance. Recognizing the implications, NASCAR turned to TotalSim to aid in accelerating a solution.
Addressing this complex issue—especially within the tight timelines of motorsports—required more than just engineering expertise. It required substantial computational power. That’s where the Ohio Supercomputer Center (OSC) came into play.
Greg Padgett, senior computational fluid dynamics (CFD) engineer at TotalSim, led the thermal analysis effort in conjunction with NASCAR. Although TotalSim had in-house capabilities, the project’s scope and timeline of about two months made OSC’s resources essential.
“When NASCAR approached us, they needed to test a lot of designs quickly. OSC was the natural choice,” Padgett explained.
NASCAR’s engineers proposed a short exhaust system to redirect heat away from the cabin. However, before the design could be implemented, it needed to undergo rigorous testing to ensure its effectiveness under racing conditions. TotalSim started by running simulations to replicate a street circuit’s challenging cooling scenario, which involves slower speeds and heavy braking.
The simulations tested several design options, including the new exhaust system, which featured a shorter muffler that improved cooling airflow and reduced heat recirculation. Additional modifications included redesigned exhaust and sealing panels to prevent hot air from spreading along the chassis (the main load-bearing part of the car's frame, where the engine and suspension are attached) and along the cockpit walls.
Using OSC’s powerful computational resources, TotalSim ran Siemens’ Simcenter STAR-CCM+ simulations on a full model of the NextGen car, exploring various cooling designs, including the proposed short exhaust system. The simulations accurately modeled heat transfer—conductive, convective and radiative—across the car’s materials, such as the exhaust assemblies, carbon fiber panels and reflective films. This detailed analysis provided critical data for decision-making.
Padgett and his team then used OSC’s Open OnDemand web portal to dive into the results of the simulation with the interactive GPU nodes to save time copying the massive simulation files. Open OnDemand helped speed up the processing and data review once the runs were completed.
NASCAR took advantage of the efficient workflow, automated meshing and parallel solver in STAR-CCM+ to leverage OSC computing resources and reach a solution with full confidence in the result. This would have been either impossible or would have taken far too long to complete with any other software and the multi-physics challenge of this model.
“We needed hundreds of cores and a lot of storage space to run these simulations,” Padgett said. “The computing power OSC provided allowed us to process the results in a fraction of the time it would have taken in-house.”
Prior to these simulations, NASCAR collected Forward Looking Infrared (FLIR) data from a track test. This data was used to validate and correlate the simulation results, showing almost identical hotspots between the FLIR track data and the simulation baseline. This validation gave TotalSim and NASCAR the assurance to proceed with testing new concepts and implement the short exhaust design in its cars on the track today. The solution highlights the power of high performance computing in solving real-world problems, especially in the fast-paced world of motorsports.
“It’s rewarding to work with a partner like NASCAR, knowing that the solutions we help develop could be racing on track just weeks after testing,” Padgett said. “And with OSC’s help, we can continue to deliver those solutions on an expedited timeline.”
Written by Lexi Biasi
The Ohio Supercomputer Center (OSC) addresses the rising computational demands of academic and industrial research communities by providing a robust shared infrastructure and proven expertise in advanced modeling, simulation and analysis. OSC empowers scientists with the services essential to making extraordinary discoveries and innovations, partners with businesses and industry to leverage computational science as a competitive force in the global knowledge economy and leads efforts to equip the workforce with the key technology skills required for 21st century jobs.
