2021/10/01 by Paul Fischer, Elia Merzari, Fischer, Paul +19
Engineering · #35-04 #Computational Fluid Dynamics and Aerodynamics #Computational Physics (physics.comp-ph) #D.0 #F.2 #FOS: Physical sciences #G.2 #G.4 #I.6 #J.2 #Nuclear Engineering Thermal-Hydraulics #Nuclear reactor physics and engineering
paper · pdf · doi:10.48550/arxiv.2110.01716
openalex publication_date 2021/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Nek5000/RS is a highly-performant open-source spectral element code for 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 high-order discretizations that realize the same (or lower) cost per gridpoint as traditional low-order methods. 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 Summit, Nek5000/RS has recently achieved an milestone in the simulation of nuclear reactors: the first full-core computational fluid dynamics simulations of reactor cores, including pebble beds with > 350,000 pebbles and 98M elements advanced in less than 0.25 seconds per Navier-Stokes timestep. With carefully tuned algorithms, it is possible to simulate a single flow-through time for a full reactor core in less than six hours on all of Summit.