Heat Transfer Limitation of a Micro Heat Pipe

An analytical expression for the heat transport capability of micro heat pipe is derived. The vapor continuum limitation has been considered in deriving the heat transport capability of a micro heat pipe. As the micro heat pipe uses sharp-cornered square, triangular, or other polygonal channels that can serve as capillary arteries, its transport capability depends on the capillary limit. It has been shown that the operating limit of the micro heat pipe depends on the vapor continuum limitation, capillary limit, and the gravity.