Study of the heat transfer performance of gravity heat pipes based on lattice Boltzmann surface modification

Surface modification is an important means to improve boiling heat transfer. Based on the research of surface wettability, this paper briefly describes the experimental and numerical simulation research on enhancing heat transfer of gravity heat pipe by changing surface wettability. According to the microscopic nature and mesoscopic characteristics of lattice Boltzmann method, the gas-liquid model of pseudo-potential lattice Boltzmann method was used to simulate the heat transfer process of gravity heat pipe with different wettability, and the corresponding morphology diagrams of boiling and condensation phenomena were obtained. It not only overcomes the disadvantage that it is difficult to study the bubble nucleation mechanism by arranging seed bubbles or seed droplets in advance when simulating phase transition in the macro flow model, but also overcomes the defect that Lennard-Jones potential in molecular dynamics cannot accurately describe the force between fluid molecules and wall solid molecules. Then, combining the simulated visual images and experimental results, the heat transfer mechanism of gravity heat pipes with different wetting properties is analyzed in detail. The results show that compared with ordinary heat pipes, the equivalent convection heat transfer coefficient of fully mixed wettability gravity heat pipe is increased by about 45.6 % and the total thermal resistance is reduced by about 40.2 %, which provides a theoretical basis for practical application.