Oak Ridge Reports Largest CFD Simulation Achieved on Frontier

The Georgia Tech team simulated an array of 1,500 Mach 14 rocket engines and their interacting exhaust plumes — modeling airflow at 14 times the speed of sound, where gases behave violently and unpredictably due to extreme pressure and temperature shifts. This simulation achieved a resolution of over 100 trillion grid points, thereby surpassing former records of 10 trillion grid points for a compressible CFD simulation on previous CPU-only supercomputers and 35 trillion for the quite different challenge of incompressible fluid flow simulated on the GPU-equipped Frontier by Professor P.K. Yeung’s group, which is also at Georgia Tech.

In addition to the massive increase in resolution and scale, the methodology devised by the Georgia Tech researchers sped up the time to solution four times faster and increased energy efficiency by 5.7 times over current state-of-the-art numerical methods.

“Using this technique, we can simulate much larger problems than before. And not only can they be larger, but our current results suggest they are more accurate,” said Spencer Bryngelson, an assistant professor in Georgia Tech’s College of Computing who led the project with Georgia Tech colleague (and office neighbor) Florian Schäfer, who’s also an assistant professor in computing. “In contrast, P.K.’s incompressible flow simulations had quite different constraints than our compressible ones, and they were limited by costly network communication across all of Frontier. That’s a hard nut to crack. His simulations are, frankly, remarkable.”

source: ORNL’s Coury Turczyn