Heat pipe is a heat transfer element for efficient heat transfer based on internal working medium phase transformation and circulating flow process. It has ultra-high thermal conductivity and excellent isothermal property. It has been widely used in chemical industry, metallurgy, aerospace, new energy, electronics, military and other fields of heat transfer and temperature control and leveling.

The working medium inside the heat pipe conducts heat transfer through a simple closed passive cycle of "heat vaporization - condensation, heat release - reflux". The operation mechanism seems simple, but in fact it is a complex process of coupled heat transfer, fluid mechanics, thermodynamics and heat and mass transfer in porous media. At the beginning, the design and research of heat pipe mainly built semi-theoretical and semi-empirical thermal resistance model, heat transfer coefficient and heat transfer limit prediction equation through the accumulation and analysis of a large number of experimental data, and supplemented by visual experiments to complete, time-consuming and labor-intensive, and the research results have a narrow range of application. In recent years, with the rapid development of computer technology and Computational Fluid Dynamic (CFD), it is possible to simulate the process of phase transition heat transfer of heat pipe. How to construct a CFD simulation model with accurate prediction and high computational efficiency to assist the design of heat pipe has become a hot research topic.

As shown in the figure above - Schematic diagram of heat flow inside the heat pipe