A simple model for puffing/micro-explosions in water-fuel emulsion droplets
A simple model for puffing/micro-explosions in water-fuel emulsion droplets
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DOI：
10.1016/j.ijheatmasstransfer.2018.11.065
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发表时间：
2019-03
影响因子：
5.2
通讯作者：
S. Sazhin;O. Rybdylova;C. Crua;M. Heikal;M. Ismael;Z. Nissar;A. Aziz
中科院分区：
文献类型：
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作者：
S. Sazhin;O. Rybdylova;C. Crua;M. Heikal;M. Ismael;Z. Nissar;A. Aziz
提出了一种新的简单的水-燃料乳化液液滴膨化/微爆炸模型。该模型是基于假设一个球形水滴位于一个较大的燃料水滴的中心。燃料用正十二烷来表示。假设燃油液滴表面温度固定，忽略燃油蒸发。利用燃料液滴表面的狄利克雷边界条件，求解了复合液滴内部的热传导方程。当水与燃料界面温度达到水的沸点时，就与膨化过程的开始有关，从而引起微爆炸。这个时间称为膨化时间，或微爆延迟时间。当燃料表面温度等于燃料的沸腾温度时，这个时间预计是可能的时间中最短的。该模型的预测结果与现有的实验数据一致。该模型预测，对于固定的水和燃料质量分数，随着燃料液滴尺寸的增加，这一时间也会增加，这与观测结果一致。
A new simple model for the puffing/micro-explosion of water-fuel emulsion droplets is suggested. The model is based on the assumption that a spherical water sub-droplet is located in the centre of a larger fuel droplet. The fuel is approximated by n-dodecane. The fuel droplet surface temperature is assumed to be fixed, and fuel evaporation is ignored. The heat conduction equation is solved inside this composite droplet with the Dirichlet boundary condition at the surface of the fuel droplet. The time instant when the temperature at the interface between water and fuel reaches the boiling temperature of water is associated with the start of the puffing process leading to micro-explosion. This time is referred to as the time to puffing, or micro-explosion delay time. When the fuel surface temperature is equal to the boiling temperature of fuel then this time is expected to be the shortest of the possible times. The predictions of the model are shown to be in agreement with available experimental data. The model predicts an increase in this time with increase in the fuel droplet size for fixed water and fuel mass fractions, in agreement with observations.