Measurements and simulations of transient characteristics of heat pipes

The rejection of heat generated by components and circuits is a very important aspect in design of electronics systems. Heat pipes are very effective, low cost elements, which can be used in cooling systems. This paper presents the modelling and measurements of the heat and mass transfer in heat pipes. The physical model includes the effects of liquid evaporation and condensation inside the heat pipe. The internal vapour flow was fully simulated using computational fluid dynamics. The theory has been compared with experimental measurements using thermographic camera and contact thermometers. The main purpose of this study is to determine the effective heat pipe thermal conductivity in transient state during start up the pipe operation and temperature increase.