Oscillatory behaviors in initial film boiling: Implications on the triggerability of single droplet vapor explosions

Abstract

A transient one-dimensional film boiling model was developed to study the film boiling dynamics that would occur when a hot spherical droplet is immersed in cold liquid. The focus of this study was to investigate the effects of noncondensible gas, liquid temperature, droplet temperature, and ambient pressure on film boiling during the initial growth phase. The results indicate that the film generally stablizes with more noncondensible gas present, higher liquid and lower droplet temperature. Small ambient pressurizations cause violent fluctuations of the film pressure while higher ambient pressure suppresses these oscillations. These qualitative behavior of film boiling around hot spherical droplet suggests that the spontaneous triggering of small-scale single droplet vapor explosions is led by the oscillatory characteristics of vapor film in its initial growth phase. © 1989, The Korean Society of Mechanical Engineers (KSME). All rights reserved.