Comparative study of the two-fluid momentum equations for multi-dimensional bubbly flows: Modification of Reynolds stress

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• 作者：Seung Jun Lee ; Byoung Jae ; Ik Kyu Park…
• 关键词：Multi ; phase flow ; CFD ; Two ; fluid model
• 刊名：Journal of Mechanical Science and Technology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：31
• 期：1
• 页码：207-214
• 全文大小：
• 刊物类别：Engineering
• 刊物主题：Mechanical Engineering; Vibration, Dynamical Systems, Control; Industrial and Production Engineering;
• 出版者：Korean Society of Steel Construction
• ISSN：1976-3824
• 卷排序：31

文摘

Two-fluid equations are widely used to obtain averaged behaviors of two-phase flows. This study addresses a problem that may arise when the two-fluid equations are used for multi-dimensional bubbly flows. If steady drag is the only accounted force for the interfacial momentum transfer, the disperse-phase velocity would be the same as the continuous-phase velocity when the flow is fully developed without gravity. However, existing momentum equations may show unphysical results in estimating the relative velocity of the dispersephase against the continuous-phase. First, we examine two types of existing momentum equations. One is the standard two-fluid momentum equation in which the disperse-phase is treated as a continuum. The other is the averaged momentum equation derived from a solid/ fluid particle motion. We show that the existing equations are not proper for multi-dimensional bubbly flows. To resolve the problem mentioned above, we modify the form of the Reynolds stress terms in the averaged momentum equation based on the solid/fluid particle motion. The proposed equation shows physically correct results for both multi-dimensional laminar and turbulent flows.