The Initial Phenomena in the Freezing Process of the Supercooled Water Flow.

Abstract

In relation to the transportation of supercooled water, physical phenomena at the intial stage of solidification of supercooled water were studied, experimentally. In order to observe the inward growth phenomenon, a duct having a rectangular cross section was used. The cold copper plates with a constant temperature were placed at the top and bottom of the duct. Two side walls of the duct were made of acrylic material in order to observe the ice growth. It was found that ice grew on the inner surface towards the upstream direction at a constant speed. It related to the surface temperature and the type of the material. On the other hand, ice growth towards inside related to the inlet water temperature, surface temperature and flow rate. Type of the ice was dendrite ice. Time lag of inward ice growth and its melting at various locations were also investigated. The mechanism of the phenomenon was suggested that the existence of dendrite ice prevent a smooth laminar flow and the supercooled water near the cooling surface is mixed with the inner flow having relatively high temperature. It causes the ice to melt at downstream faster than that of upstream.