Two-phase simulations of micro heat pipes

A two-phase model of a single micro heat pipe (MHP) and a three-dimensional network of microchannels were simulated using the finite element method. Investigation on the convergence of the models demonstrated that models with higher thermal gradient showed fluctuation with higher amplitude. Furthermore, phase change phenomenon and accumulation of the liquid phase in the sharp corners of the micro heat pipe were modelled. The effective thermal conductivity, pressure and velocity field for both phases along the length of the micro heat pipe were calculated and compared to the literature. In addition, the overloading conditions were simulated and an effective length was defined for the micro heat pipe. Consequently, the influence of liquid filling ratio on the effective length of micro heat pipe was investigated. Finally, a three-dimensional network of microchannels with two-phase flow was simulated where the circulation of the two phases was captured.