Correlation for Heat Transfer Coefficient for Rapid Cooling of Neutron Vacuum Furnaces

Developing rapid cooling technology to reduce the prolonged cooldown times of high-temperature neutron vacuum furnaces is highly desirable. Building on previous research, this study focuses on developing a correlation to describe the average Nusselt number as a function of Reynolds number and Prandtl number. Such a correlation offers a promising tool for designing compact neutron vacuum furnaces that maintain cooling performance by optimizing gas mixtures. Experiments were conducted using three pure gases, helium, nitrogen, and argon, as well as a nitrogen-helium mixture at various flow rates. The resulting correlation predicted the experimental Nusselt numbers with a maximum deviation of 15.7%, with over 66% of the data predicted with high accuracy within ±5%.