MAE 298 SEMINAR: Direct Numerical Simulation Toward Zero-carbon Fuels for Power Generation

Abstract: Mitigating climate change while providing the nation’s transportation and power generation are important to energy and environmental security. The shift to hydrogen as a clean energy carrier is one of the most promising strategies to reduce CO2 emissions in the face of increasing energy demand. While hydrogen has a few drawbacks as an energy carrier due to its low energy density, ammonia is simpler to transport and store for extended periods of time, making it an attractive carbon-free energy carrier for off-grid localized power generation and marine shipping. However, ammonia has poor reactivity and forms NOx and N2O emissions. The poor ammonia reactivity can be circumvented by partial cracking of ammonia to form ammonia/hydrogen/nitrogen blends tailored to match conventional hydrocarbon fuel properties. However, combustion of ammonia/hydrogen/nitrogen blends at high pressure, and in particular, the coupling between turbulence and fast hydrogen diffusion remains poorly understood. Exascale computing provides a unique opportunity for direct numerical simulation (DNS) of turbulent premixed combustion with ammonia/hydrogen blends and pure hydrogen to investigate pressure effects on the combustion rate and chemical pathways for NOx and N2O formation in rich-quenchlean staged configurations.

Bio: Jacqueline H. Chen is a senior scientist at the Combustion Research Facility at Sandia National Laboratories. She has contributed broadly to research in turbulent combustion elucidating turbulence-chemistry interactions in combustion through direct numerical simulations. To achieve scalable performance of DNS on heterogeneous computer architectures, she led an interdisciplinary team of computer scientists, applied mathematicians and computational scientists to develop an exascale direct numerical simulation capability for turbulent reactive flows with complex chemistry and multiphysics. She has also contributed to reduced order modeling to accelerate DNS with complex chemistry. She is a member of the United States National Academy of Engineering, and fellow of the Combustion Institute and the American Physical Society. She is an associate fellow of the AIAA. She received the Combustion Institute Bernard Lewis Gold Medal Award in 2018 for "for exceptional skill in linking high performance computing and combustion research to deliver fundamental insights into turbulence-chemistry interaction."