DATE:

Friday, September 8, 2023

TIME:

3:30 PM

LOCATION:

Virtual Zoom Seminar

SPEAKER:

Dr. Jacqueline H. Chen, Senior Scientist, Sandia National Laboratory

ABSTRACT:

Mitigating climate change while providing the nation’s transportation and electricity are important to energy and environmental security. The shift to hydrogen as a clean energy carrier is a promising strategy to reduce CO2 emissions in the face of increasing energy demand. While hydrogen has 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. 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 the coupling between turbulence and fast hydrogen diffusion remains poorly understood. Pre-exascale computing provides a unique opportunity for direct numerical simulation (DNS) of turbulent combustion with ammonia/hydrogen blends to investigate pressure effects on combustion rate,blow-off limits and NOx and N2O formation.

Exascale computing introduces challenges for data management and the need for reduced order surrogate models(ROMS) for chemical species dimension reduction and for novel in situ analysis and visualization methods. A novel model driven on-the-fly ROM recently formulated and implemented in reactive flow DNS to reduce the computational cost of chemistry will be described. Recent advances in topological segmentation, feature extraction, and statistical summarization for extreme-scale data will be discussed in the context of in situ analysis workflows that capture salient time-varying features.

Bio: Jacqueline H. Chen is a Senior Scientist 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 leads an interdisciplinary team of computer scientists, applied mathematicians and computational scientists to develop an exascale direct numerical simulation capability for turbulent combustion with complex chemistry and multi-physics.She is a member of the National Academy of Engineering and a Fellow of the Combustion Institute and the American Physical Society. She is an Associate Fellow of the AIAA. She is member of the Council for the American Association for the Advancement of Science. She received the Combustion Institute’s Bernard Lewis Gold Medal Award in 2018, the Society of Women Engineers Achievement Award in 2018, and the Department of Energy Office of Science Distinguished Scientists Fellow Award in 2020,

Department Link

HOST:

Jose Castillo (CSRC) and the Sustainable Horizons Institute CRLC Virtual Seminar Series

DOWNLOAD: