MATHEMATICAL MODEL AND THERMAL OPTIMIZATION OF A MINIATURE HEAT PIPE WITH A GROOVED WICK STRUCTURE FOR ELECTRONIC EQUIPMENT COOLING

摘要

In the present work, a one-dimensional mathematical model for a miniature heat pipe with a grooved wick structure is developed and solved numerically to yield the capillary, liquid, and vapor pressure distributions along the length of the heat pipe under steady-state conditions. The effects of the liquid-vapor interfacial shear stress, the contact angle, and the amount of liquid charge have been included in the mathematical model. In order to calculate the pressure drop in the grooved wick properly, an empirical correlation for the permeability of the trapezoidal channel is used. Experiment for measuring the maximum heat transport capability are conducted and compared with the numerical results. Physical insight into the transport phenomena in the miniature heat pipes with a grooved wick structure has been acquired and the proposed mathematical model is used for optimizing the wick structure, which results in the higher capillary pumping ability and the lower flow resistance. It is estimated that the maximum heat transport factor of a O.D. 4mm heat pipe with the optimized wick structure can be enhanced up to 12.6%.