Effects of Natural Convection in a Partially Supercooled Water Cell on the Release of Supercooling

Abstract

The flow and heat transfer characteristics of pooled water with a supercooled region have been studied experimentally using a real-time holographic interferometry technique. Pure water initially at room temperature (293.15 K) in a rectangular container is cooled on the top or bottom until the release of supercooling. The time-dependent sequential flow patterns and heat transfer of natural convection have been obtained for cases, where cooling is effected both below and above, using test containers of various heights. Furthermore, the factors affecting the release of supercooling are investigated taking into full consideration the influences of cooling wall conditions, the degree of supercooling and the heat transfer characteristics evaluated by Nusselt numbers. As a result, it is clarified that the turbulence induced by the bulk convective flow is considered to be highly important, in addition to the existence of bulk flow.