The constrained vapor bubble (CVB) which can behave as a miniature heat pipe provides a unique opportunity to study transport phenomena in the multiscale – the scale of the entire heat pipe, that of the corner meniscus and scale of the evaporating contact line. The heat pipe modeling problem is complicated by the simultaneous heat, mass and momentum transfer occurring at a moving boundary in a multiphase environment with phase change occurring at the interface. Existing models have dealt with porous or meshed wicking structure, have used correlations for flow of liquid and vapor phase and have downplayed the importance of conduction in the solid. Herein we apply some of the existing models to data obtained using our unique experimental setup which consists of a micro heat pipe formed by using pentane as the working fluid in a quartz cuvette. The limitations of such a system, which dictates the performance of the heat pipe, have been evaluated. A one-dimensional model has been created as a first approximation to compare with experimental observations. Further a three dimensional model that takes into account the solid conduction and the heat transfer and fluid dynamics of the vapor phase has also been coupled with a one-dimensional model of the liquid phase. The models seek to describe the experimental system in the earth's gravity environment and predict the effect of a micro-gravity environment aboard the International Space Station, on which this experiment is scheduled to fly, on the working of the heat pipe.