Steady Liquid Flow and Liquid-Vapor Interface Shapes in Different Groove Structures in Micro Heat Pipes

The paper presents a lubrication-type model of liquid flow and heat transfer in different groove structures in micro heat pipes under negligible gravity and small capillary number. In the adiabatic region the flow rate can be controlled by changing the shape of the cross-section. We have computed the flow rate as a function of geometric parameters. Determination of the vapor-liquid interface shape in the grooves requires coupling of fluid flow and heat transfer. We examined the shape of the interface when thermocapillary effect is insignificant and then consider the effect of thermocapilarity. Practical applications of our results are discussed in relation to the design and optimization of micro heat pipes.