Influence of surface properties on heat transfer during cooling under conditions of forced fluid flow

This paper presents new results of experiments with cooling nickel, stainless steel and copper balls during impacting by a submerged impinging jet in various liquids at different subcoolings to saturation temperature. Based on the conducted experiments on spherical samples with different thermal effusivity under conditions of free fluid flow and on their basis an approximate model of the occurrence of intense heat transfer regime during film boiling was developed (within the framework of this model, the intensifying effect of a submerged jet is quite naturally explained). On metals with low thermal effusivity, an increase in the temperature of transition to an intensive heat transfer regime was experimentally detected. It is advisable to check the effect of the submerged jet on ethanol, in which, with many combinations of solid bodies properties and subcoolings, micro-bubble boiling has not previously been appeared.