A Numerical Approach for Estimating the Entropy Generation in Flat Heat Pipes

Heat Pipe is a thermodynamic device which transports heat from one location to another with a very small temperature drop. Entropy generation can be considered as a significant parameter on heat pipe performance. Major reasons for entropy generation in a heat pipe system are temperature difference between cold and hot reservoirs, frictional losses in the working fluid flows and vapor temperature/pressure drop along heat pipe. The objective of the present work is to estimate the entropy generation in a flat heat pipe. A computational model is developed for the analysis of the transient operation of a flat heat pipe. The analysis involves the solution of two dimensional continuity, momentum and energy equations in the vapor core with the transport equations for a porous medium in the wick. The entropy generation depends on both temperature and velocity variations of vapor and liquid. Alternating Direction Implicit (ADI) scheme is used to convert the partial differential equations into finite difference equa...