THEORETICAL-ANALYSIS OF THE MAXIMUM HEAT-TRANSPORT IN TRIANGULAR GROOVES - A STUDY OF IDEALIZED MICRO HEAT PIPES

A mathematical model for predicting the minimum meniscus radius and th e maximum heat transport in triangular grooves is presented. In this m odel, a method for determining the theoretical minimum meniscus radius was developed and used to calculate the capillary heat transport limi t based on the physical characteristics and geometry of the capillary grooves. A control volume technique was employed to determine the flow characteristics of the micro heat pipe, in an effort to incorporate t he size and shape of the grooves and the effects of the frictional liq uid-vapor interaction. In Order to compare the heat transport and flow characteristics, a hydraulic diameter, which incorporated these effec ts, was defined and the resulting model was solved numerically. The re sults indicate that the heat transport capacity of micro heat pipes is strongly dependent on the apex channel angle: of the liquid arteries, the contact angle of the liquid flow, the length of the heat pipe, th e vapor flow velocity and characteristics, and the tilt angle. The ana lysis presented here provides a mechanism whereby the groove geometry can be optimized with respect to these parameters in order to obtain t he maximum heat transport capacity for micro heat pipes utilizing axia l grooves as the capillary structure.