ANALYTICAL MODELING OF THE STARTUP CHARACTERISTICS OF ASYMMETRICAL FLAT-PLATE AND DISK-SHAPED HEAT PIPES

An analytical model is developed for the startup transient of asymmetr ical flat-plate and disk-shaped heat pipes. The model solves the prope r transient heat conduction equations for the heat pipe wall and liqui d-wick regions. A quasi-steady state, pseudo three-dimensional approxi mation is used for the vapor transient behavior. The heat transfer wit hin the wall and liquid-wick regions is coupled with the vapor phase a t the liquid-vapor interfaces. Analytical solutions of temperature, va por velocity, and vapor pressure distributions are obtained based on a n in-depth integral method. Results covering the entire startup transi ent are presented for disk-shaped and flat-plate heat pipes. (C) 1998 Elsevier Science Ltd. All rights reserved.