Evaporation and breakup effects in the shock-driven multiphase instability
Evaporation and breakup effects in the shock-driven multiphase instability
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DOI：
10.1017/jfm.2020.871
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发表时间：
2020-12
影响因子：
3.7
通讯作者：
Vasco Duke-Walker;W. Maxon;Sahir R. Almuhna;J. McFarland
中科院分区：
文献类型：
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作者：
Vasco Duke-Walker;W. Maxon;Sahir R. Almuhna;J. McFarland
摘要液滴的蒸发和破碎在激波驱动多相不稳定性的许多应用中是常见的，例如在液体燃料爆震发动机、多相喷射泵和涡轮以及液体颗粒（即化学或生物制剂）的爆炸分散中。本文通过数值模拟，考虑了蒸发和液滴破碎对湍流诱导混合的影响，并与实验结果进行了比较。蒸发模型验证对以前的实验数据。的模拟和粒子模型的能力，然后证明通过定性比较与实验结果的破碎效果可以忽略不计（即小液滴）。模拟结果进一步探讨量化的蒸发（即混合增强）的影响，在雪上，提供进一步的洞察实验结果。一个新的破碎模型，来自以前的工作，然后提出了低雷诺数（低于500），低韦伯数（低于100）液滴在冲击驱动的多相不稳定。破碎模型的能力，然后证明通过与实验结果的比较，破碎效果是显着的（较大的液滴尺寸）。最后，模拟结果被用来突出破碎参数的蒸发率和大规模混合在SSTO的重要性。总体而言，它表明，蒸发是由大规模的流体动力学不稳定性，的SNOW增强，和液滴的分裂显着增加的不稳定性的强度，和液滴蒸发率。
Abstract Evaporation and breakup of liquid droplets are common in many applications of the shock-driven multiphase instability (SDMI), such as in liquid-fuelled detonation engines, multiphase ejector pumps and turbines and explosive dispersal of liquid particles (i.e. chemical or biological agents). In this paper, the effects of evaporation and breakup of droplets on the mixing induced by the SDMI are considered through simulations and compared with experimental results. The evaporation model is validated against previous experimental data. The capabilities of the simulations and particle models are then demonstrated through a qualitative comparison with experimental results where breakup effects are negligible (i.e. small droplets). The simulation results are explored further to quantify the effects of evaporation (i.e. mixing enhancement) in the SDMI, providing further insight into the experimental results. A new breakup model, derived from previous works, is then presented for low Reynolds number (below 500), low Weber number (below 100) droplets in a shock-driven multiphase instability. The breakup model capabilities are then demonstrated through a comparison with experimental results where breakup effects are significant (larger droplet sizes). Finally, the simulation results are used to highlight the importance of breakup parameters on the evaporation rate and large-scale mixing in the SDMI. Overall, it is shown that evaporation is enhanced by the large-scale hydrodynamics instability, the SDMI, and that breakup of the droplets significantly increases the strength of the instability, and rate of droplet evaporation.