Fitting parameter estimations for droplet breakage rate models
Fitting parameter estimations for droplet breakage rate models
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DOI：
10.1063/5.0173987
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发表时间：
2024-01
影响因子：
4.6
通讯作者：
Krishnamurthy Ravichandar;R. D. Vigil;Michael G. Olsen
中科院分区：
文献类型：
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作者：
Krishnamurthy Ravichandar;R. D. Vigil;Michael G. Olsen
化学过程工程单元操作，如溶剂萃取、液-液化学反应和乳化液处理，都依赖于湍流的液-液液滴流动动力学。在这些应用中使用的设备的设计和操作通常以液滴破碎的理论模型为指导。虽然已经开发了几种搅拌液体乳剂中液滴破裂的模型，但它们的实用性有限，因为它们包含了必须通过使用特定流体配对和相关流动配置进行实验来确定的拟合因素。需要获得实验数据来确定模型常数是一个重大的缺点，它阻碍了断裂模型在设计和优化工艺设备中的广泛使用。在这项工作中，我们制定了解析表达式来预测两种常用的破损率模型中与液滴破损时间相关的拟合参数的值，而无需进行实证研究。这些方程是通过使用所考虑的两种破裂模型中的基本假设推导出来的，即液滴破裂是相关变形和恢复应力之间竞争的结果。利用在均匀湍流von Kármán箱中进行的实验数据以及先前发表的非均匀流动装置中液滴破裂的研究数据来验证所导出的破裂时间参数方程。一般来说，用推导的方程拟合参数得到的预测结果与实验结果吻合得很好。
Chemical process engineering unit operations such as solvent extraction, liquid–liquid chemical reactions, and emulsion processing are all dependent on turbulent liquid–liquid droplet flow dynamics. The design and operation of equipment used in these applications is often guided by theoretical models for droplet breakup. Although several models for droplet breakage in agitated liquid emulsions have been developed, their utility is limited because they incorporate fitting factors that must be determined empirically by performing experiments using a specific fluid pairing and relevant flow configuration. The need to acquire experimental data to determine model constants is a significant drawback that hinders widespread use of breakage models to design and optimize process equipment. In this work, analytical expressions are formulated to predict the value of a fitting parameter associated with droplet breakage time for two commonly used breakage rate models without having to perform empirical studies. These equations were derived by using the underlying assumptions within each of the two breakage models considered, namely, that droplet breakage is a result of the competition between relevant deformation and restorative stresses. Data from experiments conducted in a homogeneous turbulent von Kármán box as well as from previously published investigations of droplet breakage in heterogeneous flow devices were utilized to validate the derived equations for the breakage time parameters. In general, good agreement was observed between predictions obtained using the derived equations for fitting parameters and those obtained from experiments.