The effect of water cooling conditions on the mechanisms of porous ice formation

Abstract

Experimental data on the freezing rate and formation of cylindrical and spherical gas inclusions occurring in ice during the cooling of distilled water being in equilibrium with air at different initial temperatures of water and air and during the nonuniform cooling of a vessel with water have been obtained. The shape, size, and location of emerging gas formations are explained in a qualitative manner. It is shown that, with sufficiently slow freezing of water, conditions are created for the formation of thin (0.05 to 0.4 mm) and long (5 to 40 mm) fairly uniform gas tubes. With the acceleration of water freezing, the length of the gas tubes decreases significantly, whereas spherical gas inclusions are formed. The main processes occurring in water are mathematically analyzed. The specified processes include the temperature reduction, variation of the water aggregate state, gas concentration, and creation of conditions for the formation of gas cavities. The quantitative estimates of typical sizes of the forming tubular pores and the distances between them are obtained.