HPC-Accelerated Development of Ultra-High Efficiency Hydrogen Propulsion Systems Wins 2022 HPCwire Award

Madison, Wisconsin—January 5, 2023Convergent Science, Argonne National Laboratory, and Aramco Americas’ Detroit Research Center received the 2022 HPCwire Editors’ Choice Award for the Best Use of HPC in Industry. The three recipients were nominated for developing a high-fidelity, HPC-enabled, analysis-led design (ALD) process to accelerate the advancement of clean, high-efficiency propulsion systems.

The researchers from Convergent Science, Argonne, and Aramco Americas focused their efforts on hydrogen-powered propulsion systems. Hydrogen has garnered significant interest in recent years because of its potential to be used as a zero-carbon fuel in the transportation sector. The team’s goal was to establish an efficient ALD process for developing ultra-high efficiency hydrogen propulsion systems. This work is part of a larger effort known as the Initiative for Modeling Propulsion and Carbon-neutral Transportation (IMPACT) Consortium.

The team used CONVERGE to conduct high-fidelity computational fluid dynamics (CFD) studies and investigate different simulation phenomena, including hydrogen chemical kinetics, supersonic hydrogen jets, and fuel-air mixing.

CONVERGE simulations of hydrogen-air mixing using LES (left) and RANS (right) turbulence models, run by Dr. Bifen Wu at Argonne National Laboratory.

Accurate fuel chemistry is key to any hydrogen combustion simulation. Using 0D, 1D, and 3D simulations, the team identified shortcomings in existing hydrogen kinetic mechanisms and employed a Monte-Carlo sampling approach to optimize the reaction rate coefficients. The optimized hydrogen mechanism led to significantly improved predictions of in-cylinder pressures and heat release rates.

In addition, capturing hydrogen injection and fuel-air mixing is critical for accurate predictions of hydrogen combustion and emissions. The team tested different RANS and LES turbulence models to predict the mixture distribution in the combustion cylinder and various meshing strategies to capture the behavior of the hydrogen jet.

“Injecting hydrogen at very high pressures results in an underexpanded jet, meaning that the flow at the nozzle exit is supersonic,” says Dr. Roberto Torelli, Senior Research Scientist at Argonne. “This requires very fine meshes and very small time-steps to achieve an accurate solution, but this makes the simulation very expensive.”

For CFD to be an effective design tool for hydrogen propulsion systems, turnaround time on simulation results must be reasonable. By optimizing their meshing strategy, the team was able to reduce simulation runtime by more than 50%, while maintaining the accuracy of the solution. The team is also exploring innovative methods that could lead to another 80% runtime reduction to further improve the computational efficiency of hydrogen combustion simulations.

“The analysis-led design process we developed will expedite the adoption of clean, highly efficient hydrogen propulsion systems and enable an accelerated transition to a clean, low-carbon energy system,” says Dr. Yuanjiang Pei, Computational Modeling Team Lead at Aramco Americas.

The interdisciplinary team has worked together on previous projects with the aim of developing cleaner propulsion systems, for which they won HPCwire Awards in 2019, 2020, and 2021. Their prior research efforts have focused on combining HPC and artificial intelligence to accelerate the design of a highly efficient engine, using supercomputing to resolve micron-scale manufacturing defects in fuel injectors and achieve better mixing predictions, and applying HPC-enabled high-fidelity simulations to evaluate engine cold operations to reduce emissions.

“Collaborating with the brilliant engineers at Aramco Americas and Argonne has allowed us to make significant progress toward a more sustainable future,” says Dr. Kelly Senecal, Co-Owner and Vice President of Convergent Science. “We’re incredibly honored to receive this HPCwire Award, and I look forward to continuing our fruitful partnership.”

About Convergent Science

Headquartered in Madison, Wisconsin, Convergent Science is a global leader in computational fluid dynamics (CFD) software. Our mission is to enable our customers to perform revolutionary CFD simulations by creating accurate, versatile, user-friendly software and providing unparalleled support.

Our flagship product, CONVERGE, is an innovative CFD software that eliminates the grid generation bottleneck through autonomous meshing and features a suite of advanced physical models, fully coupled detailed chemistry, and the ability to easily accommodate moving geometries. CONVERGE is revolutionizing the CFD industry and shifting the paradigm toward predictive CFD.

For more information about Convergent Science, please visit


Published January 5, 2023