Numerical simulations of droplet evaporation and breakup effects on heterogeneous detonations
Numerical simulations of droplet evaporation and breakup effects on heterogeneous detonations
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DOI：
10.1016/j.combustflame.2023.113035
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发表时间：
2023-11
影响因子：
4.4
通讯作者：
Ben Musick;Manoj Paudel;Praveen Ramaprabhu;Jacob A. McFarland
中科院分区：
文献类型：
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作者：
Ben Musick;Manoj Paudel;Praveen Ramaprabhu;Jacob A. McFarland
液滴的蒸发和破碎是液体燃料多相爆轰过程中的关键现象。了解每个过程的相关条件和时间对于预测真实的世界行为至关重要。本文通过Euler-Lagrange（EL）数值模拟，研究了蒸发和破碎对多相爆轰过程的影响。不同液滴大小的正十二烷（C12 H26）与氧气（O2）的反应，利用一步全球反应机制。液滴过程建模使用依赖于温度的热物理性质，通过液-气相变，并进入超临界状态。两个气动破碎模型被认为是（基于理论化的流体动力学不稳定机制）从经验和理论的方法。爆轰波速度赤字被观察到是敏感的破碎和蒸发时间。结果表明，液滴重新分配燃料蒸汽质量在其寿命，扰动当量比，并创建蒸汽丰富的地区，不能完全反应。结果表明，随着总蒸发时间的减少（破碎时间缩短），爆轰结构变得更像理想的气相爆轰情况。
Evaporation and breakup of droplets are critical phenomena in the liquid-fueled, multiphase detonation process. Understanding the relevant conditions and times for each process is crucial for predicting real world behavior. In this paper, the effects of evaporation and breakup on the multiphase detonation process will be explored through Euler-Lagrange (EL) simulations. Various droplet sizes of n-dodecane (C 12 H 26) are reacted with oxygen (O 2) utilizing a single-step global reaction mechanism. Droplet processes are modeled using temperature dependent thermophysical properties through the liquid-gas phase change and into the supercritical regime. Two aerodynamic breakup models are considered (based on theorized hydrodynamic instability mechanisms) from both empirical and theoretical approaches. Detonation wave velocity deficits are observed to be sensitive to breakup and evaporation time. It is shown that droplets redistribute fuel vapor mass over their lifetime, perturbing the equivalence ratio and creating vapor rich regions that cannot fully react. It was shown that as the total evaporation time decreases (shorter breakup time), the detonation structure becomes more like the idealized gaseous detonation case.