Modeling of Regime Transition in Bubble Columns with Stability Condition

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• 作者：Jianhua Chen ; Ning Yang ; Wei Ge ; Jinghai Li
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2009
• 出版时间：January 7, 2009
• 年：2009
• 卷：48
• 期：1
• 页码：290-301
• 全文大小：516K
• 年卷期：v.48,no.1(January 7, 2009)
• ISSN：1520-5045

文摘

Understanding the physical essence of regime transition is of crucial importance for the modeling and simulation of hydrodynamics and heat and mass transfer in bubble columns. The regime transition of the air−water system has been captured by the dual-bubble-size (DBS) model in our previous work [Yang et al. Chem. Eng. Sci. 2007, 62, 6978−6991] as a jump change from one minimum point of the stability criterion to the other. The DBS model features the incorporation of a stability condition with hydrodynamic conservation equations through the analysis of compromise between dominant mechanisms. This work reiterates our previous work and further explores some remaining issues and underlying physics related to the jump change by analyzing the trajectory of global minimum points in the three-dimensional space of structural parameters. The influence of drag coefficient correlations on the model prediction is investigated. The effect of liquid viscosity on regime transition is evaluated using the DBS model for saccharose and glycerin systems. The dual effects of liquid viscosity reported in literature, namely, suppressing the regime transition while slightly increasing viscosity and destabilizing the homogeneous regime at higher viscosity, can be reasonably predicted with this model. Finally, the concept of the compromise between dominant mechanisms is extended to understand the bubble behavior at different scales and its relationship with stability condition.