The Minimum Meniscus Radius and Capillary Heat Transport Limit in Micro Heat Pipes

Abstract

Based on the momentum conservation and Laplace-Young equations, an analytical expression for the minimum meniscus radius was derived and an expression for the maximum capillary heat transport limit in micro/small heat pipes was obtained. These expressions incorporated the shear stresses at the liquid/solid and liquid/vapor interfaces, contact angle effects, vapor pressure drop, tilt angle, groove dimensions, and channel angle effects. In order to verify the expressions derived herein, comparisons with experimental data from triangular grooves and micro heat pipes were made; they demonstrated that these equations can be used to predict the maximum capillary heat transport in the micro/small triangular grooves or micro heat pipes with a higher degree of accuracy, and they can explain the behavior better than previously developed models.