Exascale Simulations of Fusion and Fission Systems
<|reference_start|>Exascale Simulations of Fusion and Fission Systems: We discuss pioneering heat and fluid flow simulations of fusion and fission energy systems with NekRS on exascale computing facilities, including Frontier and Aurora. The Argonne-based code, NekRS, is a highly-performant open-source code for the simulation of incompressible and low-Mach fluid flow, heat transfer, and combustion with a particular focus on turbulent flows in complex domains. It is based on rapidly convergent high-order spectral element discretizations that feature minimal numerical dissipation and dispersion. State-of-the-art multilevel preconditioners, efficient high-order time-splitting methods, and runtime-adaptive communication strategies are built on a fast OCCA-based kernel library, libParanumal, to provide scalability and portability across the spectrum of current and future high-performance computing platforms. On Frontier, Nek5000/RS has achieved an unprecedented milestone in breaching over 1 trillion degrees of freedom with the spectral element methods for the simulation of the CHIMERA fusion technology testing platform. We also demonstrate for the first time the use of high-order overset grids at scale.<|reference_end|>
@article{min2024exascale,
    title={Exascale Simulations of Fusion and Fission Systems},
    author={Misun Min, Yu-Hsiang Lan, Paul Fischer, Elia Merzari, Tri Nguyen,
  Haomin Yuan, Patrick Shriwise, Stefan Kerkemeier, Andrew Davis, Aleksandr
  Dubas, Rupert Eardly, Rob Akers, Thilina Rathnayake, Tim Warburton},
    journal={arXiv preprint arXiv:2409.19119},
    year={2024},
    archivePrefix={arXiv},
    eprint={2409.19119},
    primaryClass={cs.CE}
}