Advanced Thermal–Hydraulics and Multiphase Flow Simulation for Nuclear Energy Systems

Dear Colleagues,

The continuous evolution of nuclear energy technologies—encompassing advanced fission reactors, small modular reactors (SMRs), and fusion energy systems—demands an increasingly sophisticated understanding of thermal–hydraulic phenomena. As these systems move toward higher power densities and more compact designs, the role of multiphase flow and advanced simulation becomes a cornerstone for ensuring operational safety, economic viability, and long-term reliability. The complex interplay between heat transfer, fluid dynamics, and phase-change processes under extreme conditions remains one of the most significant challenges in modern nuclear engineering.

This Special Issue, titled “Advanced Thermal–Hydraulics and Multiphase Flow Simulation for Nuclear Energy Systems,” seeks to capture the latest progress in the modeling, simulation, and experimental characterization of thermal-fluid behavior across the entire nuclear energy landscape. From the fundamental physics of two-phase flow to the integration of high-fidelity multi-physics codes, this Issue aims to provide a comprehensive state-of-the-art overview of how advanced thermal–hydraulics are shaping the future of nuclear energy.

We invite researchers and engineers to submit original research articles and comprehensive reviews that address the diverse aspects of thermal–hydraulics and multiphase flows. We particularly welcome contributions that focus on innovative numerical methodologies, multi-scale modeling approaches, and robust validation techniques that bridge the gap between theoretical research and practical nuclear applications. By facilitating the exchange of cutting-edge knowledge, this Special Issue will contribute to the development of safer and more efficient nuclear power systems for a sustainable future.

Topics of interest for publication include, but are not limited to, the following:

• Fundamental physics and mechanistic modeling of multiphase flows and heat transfer in nuclear systems;
• Advanced numerical algorithms and computational frameworks for thermal–hydraulic simulations;
• Thermal–hydraulic performance and optimization of advanced reactor concepts (Gen-IV, SMRs, etc.);
• Phase-change heat transfer: boiling, condensation, and evaporation in nuclear environments;
• Heat and mass transfer phenomena in nuclear cooling, fuel cycles, and waste management;
• Verification, Validation, and Uncertainty Quantification (VV&UQ) of thermal–hydraulic codes and system-level thermal–hydraulic transients;
• Innovative heat removal technologies and thermal management strategies;
• Integration of Artificial Intelligence and machine learning in nuclear thermal-fluid simulations.

Dr. Ji Hwan Lim
Guest Editor

Manuscript Submission Information

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