Analysis of Asymmetric Disk-Shaped and Flat-Plate Heat Pipes

Abstract
An analytical investigation and conceptual design of a disk-shaped asymmetric heat pipe is presented in this work. Using the conservative formulations for the steady incompressible vapor and liquid flow for a disk-shaped heat pipe, an in-depth integral analysis is applied. Analytical results for the asymmetric vapor velocity profile, the vapor and liquid pressure distributions, and the vapor temperature distribution in the heat pipe are obtained and compared to those of rectangular flat-plate heat pipe. The analysis establishes the physics of the process and the intrawick interactions for the disk-shaped heat pipe. The effects of variations in the thicknesses of the vapor channel and the wick as well as the heat pipe on the performance of both disk-shaped and rectangular flat-plate heat pipes are analyzed in detail and compared with each other. The factors limiting heat pipe performance are discussed and the results show that the disk-shaped heat pipe, while utilizing a smaller surface area and being more adaptable to several application areas, significantly increases the heat transfer capability per unit surface area compared to rectangular flat-plate heat pipe.