The 10th Asian Symposium on Computational Heat Transfer and Fluid Flow ( ASCHT2025)

Numerical simulations using five turbulence models (Transition k-kl-ω, Realizable k-ε, RNG k-ε, Reynolds stress-BSL, and SST k-ω) were conducted for supercritical water flow in a vertically heated loop at three distinct mass fluxes (G = 500, 1000 and 1500 kg/m²s). This study aimed to identify suitable turbulence models for different operating conditions. Turbulence kinetic energy and turbulence dissipation rate at key local positions along the flow direction were compared to analyze the impact of variations between turbulence models on the simulation results. The results demonstrate that differences in the treatment of the dissipation term within the governing equations of the various turbulence models lead to discrepancies in the distributions of turbulence kinetic energy and dissipation rate at specific local positions. These discrepancies affect the iterative calculation of fluid properties, such as temperature and c_p, consequently influencing the predictive capability of the turbulence models regarding the heat transfer process.
 

supercritical water, turbulence models, vertical loop, validation