Simulation of mass transfer from an oscillating microdroplet
Simulation of mass transfer from an oscillating microdroplet
复制标题
振荡微滴的传质模拟
DOI：
10.1016/j.ijheatmasstransfer.2004.11.008
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
E. James Davis
中科院分区：
文献类型：
--
作者：
Guoqiang Guan;Jiahua Zhu;Sulan Xia;Zhao Feng;E. James Davis
微米级和亚微米级气载微液滴的传质现象广泛存在于各种化工过程、材料科学和大气现象中，如撞击流反应器和污染物非稳态扩散等，微液滴振荡可以显著提高传质速率。然而，以前的理论并不能充分预测这种传质的增强，特别是在相对大振幅振荡的情况下。我们已经分析了具有足够低的蒸汽压的振荡微滴的缓慢蒸发，使得它保持在周围的气体温度下，并且具有可忽略的小的直径变化率。我们数值求解了控制对流扩散方程，得到了作为系统参数函数的舍伍德数。这些包括振荡频率、最大速度和初始微滴直径。理论结果进行了比较，从文献中的十二烷醇微滴悬浮在电动平衡（EDB）和振荡通过改变直流悬浮电压和交流振幅和频率的传质数据。预测的舍伍德数与实验结果一致，平均偏差为9.2%。分析表明，一个明显的周期性变化的传质速率或舍伍德数的周期是振荡的微滴的周期的一半。
Mass transfer from micrometer and sub-micrometer airborne microdroplets arises in various chemical process, material science, and atmospheric phenomena, such as impinging flow reactor and unsteady pollutant diffusion, where microdroplet oscillation can substantially increase the mass transfer rate. Previous theories, however, do not adequately predict this enhancement of mass transfer, especially in the case of relatively large-amplitude oscillations. We have analyzed slow evaporation of an oscillating microdroplet having a sufficiently low vapor pressure such that it remains at the surrounding gas temperature and has a negligibly small rate of change of diameter. We solved the governing convective diffusion equation numerically to obtain the Sherwood number as a function of the system parameters. These include the oscillation frequency, the maximum velocity, and the initial microdroplet diameter. The theoretical results are compared with mass transfer data from the literature for a dodecanol microdroplet levitated in an electrodynamic balance (EDB) and oscillated by varying the dc levitation voltage and the ac amplitude and frequency. The predicted Sherwood numbers agree with the experimental results with a mean deviation of 9.2%. The analysis shows a distinct periodic change in the mass transfer rate or Sherwood number with a period that is one-half the period of oscillation of the microdroplet.
影响因子：
4.1
作者：
HIRT, CW;AMSDEN, AA;COOK, JL
通讯作者：
COOK, JL