Forced convection film boiling in the stagnation region of a molten drop and its application to vapour explosions

Abstract

This work was undertaken as part of an investigation into the heat transfer mechanism related to thermal explosion. The theoretical model of forced convection film boiling in the stagnation point region of an axi-symmetrical molten drop is presented. The model is particularly relevant to the coarse pre-mixing stage of vapour explosion: it takes account of the fact that, at this stage, the hot substance is molten. Stagnation point momentum (Falkner-Skan) and energy equations, for cold and hot liquids and for the vapour layer, were solved numerically, with a wide range of boundary-matching conditions at the interfaces. The model presented, by covering a wide range of the conditions and parameters, is more general than the cases discussed in other publications. For this reason the results can be applied not only to the coarse pre-mixing stage of vapour explosion, but also to other situations, where three-phase forced convection occurs on an axi-symmetrical body.