Reserch On Silicon Micro Flat Heat Pipes With Axial Grooves

The theoretical analysis and numerical simulation of a silicon micro flat heat pipe with axially micromachining triangle grooves are described in this paper. This micro flat heat pipe not only have good prospect on cooling of high-power-density IC chips, but also can be used in many other fields such as aviation, spaceflight, biology and medicine.Firstly the working principle and operation limits of MHP (Micro Heat Pipe) are introduced. Then numerical simulation is undertaken to analyze the thermal performance of the micro flat heat pipe. After a one-dimensional steady-state model is established, the flow of liquid and vapor in triangle grooves are numerically solved using MATLAB. The effect of interfacial and vapor shear stress on the heat transport performance is considered more precisely. The results obtained from this simulation contain axial variation of pressure difference between vapor and liquid, velocity of liquid and vapor and film thickness. In addition maximum heat transport capacity of MHP is calculated. The results predicted by the model are compared with the published results in literature and show good agreement. Moreover the heat transfer characteristics in the evaporating thin film region is studied. Transverse distributions of liquid film, heat transfer coefficient, revised capillary force and interfacial temperature are calculated. And the effect of disjoining pressure on the heat transfer performance in the evaporating thin film region is also investigated. These numerical results and relevant analyses can be used in design and optimization of this micro plat heat pipe prototypes.