A Review of Heat Pipe Visualization Methods

Heat pipe is an efficient heat transfer device by means of the phase transition of the working fluid. Due to the complex heat and mass transfer inside, it is difficult to fully disclose its heat and mass transfer mechanism by traditional theoretical or experimental research methods. The visualization method, which can be used to directly observe the phenomenon of two-phase flow and phase change heat transfer of the working fluid inside heat pipe, becomes an important approach to provide insights into the heat pipe. The basic principle and implementation mode of visualization methods such as CFD (Computational Fluid Dynamics) simulation, experimental imaging method using the transparent material and transparent rendering are described. The new heat pipe visualization methods are reviewed, with an emphasis on those experimental visualization technologies using the transparent material heat pipe. Also, the quantification limitations and challenges in the existing visualization methods are summarized. In the end, the future main research areas and potential development of heat pipe visualization research are presented.