Rapid vaporization of subcooled liquid in a capillary structure

A novel process is introduced for rapid vaporization of subcooled liquid in a capillary structure. The process consists of a low-thermal-conductivity porous wick, heated from a downward-facing grooved heating block that is in intimate contact with the upper surface of the wick structure. For such a specially configured heat transfer device, measurements show that vapor can be generated rather quickly once a sufficient amount of heat was-applied. The mechanisms leading to the rapid vaporization of liquid are numerically investigated. It is found that the low thermal conductivity of the capillar y structure and the presence of the extremely steep temperature gradients a t the fin/porous structure interface due to the rather weak natural convect ion, reflected by small-scale secondary flow cells below the heated fins, a re responsible for the rapid vaporization of subcooled liquid. (C) 2001 Els evier Science Ltd. All rights reserved.