A new approach to modelling micro-explosions in composite droplets
A new approach to modelling micro-explosions in composite droplets
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DOI：
10.1016/j.ijheatmasstransfer.2020.120238
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发表时间：
2020-11
影响因子：
5.2
通讯作者：
S. Sazhin;T. Bar-Kohany;Z. Nissar;D. Antonov;P. Strizhak;O. Rybdylova
中科院分区：
文献类型：
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作者：
S. Sazhin;T. Bar-Kohany;Z. Nissar;D. Antonov;P. Strizhak;O. Rybdylova
提出了一种模拟复合水/燃料液滴雾化和微爆炸的新方法。这种方法是基于先前的假设，即球形水水滴位于球形燃料（正十二烷）水滴的中心。用热传导方程描述了燃料液滴的加热过程，该热传导方程具有表面的Robin边界条件和燃料-水界面的连续性条件。在每个时间步得到的该方程的解析解被纳入数值代码，并用于液滴加热和蒸发的分析。考虑了液滴热膨胀的影响。使用该代码的计算结果使我们能够获得水/燃料界面温度的时间演变，以及该温度（T˙）在同一位置随时间的时间导数演变。利用原始和先前发表的实验数据，提出了两个新的成核温度T N作为T˙函数的相关性，在0≤T˙≤10.6 K/s范围内有效。利用这些相关关系和从分析中推断出的T˙值，得到了水-燃料界面成核温度T N的时间演变。将T N预测值与该界面温度T w进行比较，将T w= T N的时间瞬间与膨化/微爆炸开始的时间瞬间相关联。
A new approach to modelling puffing and micro-explosion in composite water/fuel droplets is proposed. This approach is based on the assumption previously made that a spherical water sub-droplet is located in the centre of a spherical fuel (n-dodecane) droplet. The heating of a fuel droplet is described by the heat conduction equation with the Robin boundary condition at its surface and continuity conditions at the fuel-water interface. The analytical solution to this equation, obtained at each time step, is incorporated into the numerical code and used for the analysis of droplet heating and evaporation. The effects of droplet thermal swelling are taken into account. The results of calculations using this code allowed us to obtain the time evolution of the temperature at the water/fuel interface and the evolution of time derivative of this temperature (T˙) with time in the same location. Using the original and previously published experimental data, two new correlations for the nucleation temperatures T N as functions of T˙, valid in the range 0≤ T˙≤ 10 6 K/s, are suggested. Using these correlations and the values of T˙ inferred from the analysis, the time evolutions of the nucleation temperatures T N at the water-fuel interface are obtained. The predicted values of T N are compared with the values of temperature at this interface T w. The time instant when T w= T N is associated with the time instant when puffing/micro-explosion starts.