ANALYSIS OF HEAT TRANSFER PHENOMENA AT SUPERCRITICAL PRESSURE SUPPORTED BY A FLUID-TO-FLUID SIMILARITY THEORY

This doctoral research delves into the intricate realm of heat transfer phenomena under supercritical pressure conditions, with a particular focus on their relevance to Supercritical Water Reactors (SCWRs). The study commences by exploring proposed fluid-to-fluid similarity parameters and their implications, setting the stage for a novel approach. The core of this investigation lies in the application of a similarity theory through Computational Fluid Dynamics (CFD) methods. This theory serves as a guiding beacon to unearth counterpart operating conditions for real experiments, made feasible by our predictive models. Furthermore, this study delves into the realm of existing correlation forms, scrutinizing them under the lens of "correlation" and "prediction" modes. This analysis aims to shed light on the intricate process of validating prediction tools, while also embarking on a quest for potential enhancements. To enhance our comprehension of deteriorated heat transfer phenomena, the research takes a significant stride by characterizing a specific mode reminiscent of critical heat flux under subcritical pressures. The emergence of pseudo-Nukiyama curves is a highlight offering a promising tool for unifying the treatment of critical and deteriorated heat transfer in system codes across different pressure regimes. Moreover, the study ventures into the realm of Computational Fluid Dynamics (CFD) to assess its applicability in representing operating conditions akin to nuclear reactors. In the context of smooth and rough tube conditions, utilizing the similarity theory to draw parallels between phenomena observed with surrogate fluids and those postulated to occur in full-scale water reactors. The research findings are distilled into a coherent summary, underscoring their significance and charting pathways for future research endeavours. This comprehensive study advances our understanding of heat transfer at supercritical pressures, offering valuable insights and avenues for further exploration.