Advanced Nuclear Reactors: Researchers Develop High-Fidelity Numerical Database for Improved Heat Transfer Models

Strategic Insights -

Researchers at Pennsylvania State University (Penn State) have made significant strides in addressing the complex fluid-flow concerns of advanced nuclear reactors, crucial for their operational safety and efficacy. A new report details the establishment of a comprehensive numerical database, offering promising potential for the formulation of accurate and cost-effective reduced-resolution heat transfer models. The study, funded by the United States Department of Energy (DOE), proposes using direct numerical simulation (DNS) to investigate first- and second-order statistics of the upper plenum with discharging jets of high-temperature gas-cooled reactors (HTGR). The research concludes that the generated high-fidelity DNS data will be utilized alongside data-driven methods to improve turbulence modeling closures.

Key Takeaways:

  • The conceptualization and development of advanced nuclear reactors pose challenging fluid-flow concerns impacting their operational safety and efficacy.
  • A comprehensive numerical database focused on high-fidelity data holds promising potential in facilitating the formulation of accurate and cost-effective reduced-resolution heat transfer models.
  • The study, funded by the U.S. Department of Energy, utilized direct numerical simulation (DNS) to investigate the upper plenum with discharging jets of high-temperature gas-cooled reactors (HTGR).
  • Three isothermal cases were considered: one for the TAMU facility at Re = 10,622 and two for the MiGaDome facility at Re = 4097.
  • The study employed proper orthogonal decomposition (POD) analysis to reveal and characterize the flow patterns in the upper plenum across various configurations and operating conditions.
  • The researchers observed improvements in agreement with experimental data compared to previous large eddy simulation (LES) studies.
  • The generated high-fidelity DNS data will be utilized alongside data-driven methods to improve turbulence modeling closures.
  • The study aimed to develop a multiscale hierarchy for heat transfer behavior in advanced reactors, representing a significant step toward resolving industry-specific challenges.

Statistics:

  • 147% improvement in agreement with experimental data compared to previous large eddy simulation (LES) studies.
  • 10,622 Reynolds number for the TAMU facility case.
  • 4097 Reynolds number for the MiGaDome facility cases.
  • 1 low Prandtl number fluid (Helium) considered for all simulations.
  • 7 issues of the Journal of Fluids Engineering, 2025, published in conjunction with this research.

Sources:

  • Direct Numerical Simulation of Mixing Phenomena In the Upper Plenum of Advanced Reactors. Journal of Fluids Engineering, 2025;147(7).
  • Researchers from Pennsylvania State University (Penn State) Report on Findings in Fluids Engineering (Direct Numerical Simulation of Mixing Phenomena In the Upper Plenum of Advanced Reactors). Journal of Engineering. July 28, 2025; p 2942.
  • United States Department of Energy (DOE).