Advection-enhanced heat and mass transport from neutrally suspended droplet in simple shear flow
Advection-enhanced heat and mass transport from neutrally suspended droplet in simple shear flow
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DOI：
10.1063/5.0153117
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发表时间：
2023-06
影响因子：
4.6
通讯作者：
Yanxing Wang;David Vazquez Alvarez;Hui Wan;Ruben Gonzalez Pizarro;Fangjun Shu
中科院分区：
文献类型：
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作者：
Yanxing Wang;David Vazquez Alvarez;Hui Wan;Ruben Gonzalez Pizarro;Fangjun Shu
采用高保真数值模拟方法研究了简单剪切流场中中性悬浮液滴的对流增强传热传质过程。毛细管数在0.01至0.5的范围内，其包括小变形、大变形和液滴破裂的整个范围。雷诺数从0.01到1，包括弱平流和强平流区域。温度和质量浓度被建模为在液滴表面释放的被动标量的浓度。两个施密特数，10和100，被认为是流动平流中起作用的被动标量的运输。对于未破碎的液滴，载液和悬浮液滴之间的相互作用导致液滴周围的几种不同的流动。流体运动与标量扩散共同构成了被动标量的耦合输运机制。标量释放速率对雷诺数和Peclet数的依赖关系可以粗略地描述为一个刚性球的相关性。对于破碎液滴，在拉伸和破碎过程中，液滴周围的基本流动特征与未破碎液滴相似。标量释放速率的变化可以分解为几个阶段，对应于液滴的伸长和破碎过程。标量释放速率的变化表现出与毛细管，雷诺数和Peclet数的高度相关性。这表明，它是可行的，以开发一个经验模型，结合分裂后的子液滴的数量和尺寸分布的影响。
Advection-enhanced heat and mass transport from a single droplet neutrally suspended in a simple shear flow has been studied using high-fidelity numerical simulation. The capillary number ranges from 0.01 to 0.5, which encompasses the entire range of small deformation, large deformation, and breakup of the droplets. The Reynolds number is from 0.01 to 1, including regions of both weak and strong advection. The temperature and mass concentration are modeled as the concentration of a passive scalar released at the droplet surface. Two Schmidt numbers, 10 and 100, are considered, for which flow advection plays a role in the transport of passive scalar. For unbroken droplets, the interaction between the carrier fluid and the suspended droplet leads to several different flows around the droplet. The fluid motions together with scalar diffusion constitute a coupled transport mechanism for passive scalar. The dependence of scalar release rate on Reynolds and Peclet numbers can be roughly described by the correlation for a rigid sphere. For broken droplets, the basic flow features around the droplet during the process of elongation and breakup are similar to those of an unbroken droplet. The variation of the scalar release rate can be decomposed into several stages, corresponding to the process of droplet elongation and breakup. The variation of the scalar release rate exhibits a high correlation with the capillary, Reynolds, and Peclet numbers. This suggests that it is feasible to develop an empirical model that incorporates the effects of the number and size distributions of child droplets after breakup.