Minimum ignition temperature of gas–liquid two-phase cloud
摘要
In the dispersing process of liquid fuel or metal powder under the explosion load of a high explosive, the explosion product of central high-energy explosive expands. Flow of the explosion product with high temperature is coupled with the dispersing of fuel driven by the explosion load. When concentration of the dispersing fuel cloud and the current temperature meet critical condition for igniting the cloud, the fuel cloud will be ignited. If the dispersing fuel is ignited by the high temperature of the explosion product, the fuel cloud will burn, and the pre-designed detonation energy output cannot be achieved. Therefore, avoiding the ignition phenomenon in the process of fuel dispersion is an important issue in effective utilization of multi-phase cloud explosion energy. The minimum ignition temperature (MIT) of gas–liquid two-phase cloud is the basis for avoiding the dispersing fuel to be ignited under explosion load of a high explosive. In this study, the MITs of gas–liquid two-phase cloud of ethanol, octane, nitromethane, and isopropyl nitrate were measured. The MIT of gas–liquid two-phase cloud is a function of ignition temperature (IT) of vapor and atomization parameters of liquid fuel. The MIT of gas–liquid two-phase cloud of a liquid fuel is higher than IT of vapor of the liquid fuel. The MIT of gas–liquid two-phase cloud decreases with the decrease in droplet characteristic sizes. The prediction model of MIT of gas–liquid two-phase cloud of liquid fuel (MIT = 507 + 0.15