A linear stability analysis of a vapor film in terms of the triggering of vapor explosions

Abstract

A Detailed analytical model to explain the vapor film collapse was developed to evaluate the occurrence conditions of self triggering vapor explosions. The following conclusions were drawn based on linear stability analysis using the thermo-dynamic property of water, by linearizing and perturbing basic equations (Rayleigh-Lamb-Plesset's bubble momentum equation, the mass conservation equation, the state equation for ideal gas, and the Clausius-Clapeyron equation). The vapor film stabilizes with the reduction of the hot-liquid diameter, decreasing the condensation heat transfer coefficient, and increasing the thermal radiation coefficient. The cold-liquid viscosity and surface tension have a stabilizing effect, though this effect is negligibly small where the hot liquid diameter is over 1 mm. The analysis predicts the vapor explosion occurrence limits obtained experimentally by other researchers to within approximately 10 K.