Improved modeling of wall effects on interfacial momentum exchange for wall-bounded bubbly flows based on resolved simulations

• Published in: Chemical engineering science 2022-03, Vol.250, p.117332, Article 117332
• Main Authors: Kim, Dongjoo, Kim, Jungwoo
• Format: Article
• Language: English
• Subjects: Bubble Reynolds number; Bubbly flow; Two-fluid model; Wall effect
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2021.117332

•We propose a new wall force model which is accurate and reliable for bubbly flow.•The present wall model is based on resolved simulations.•It could give good predictions without a case-by-case tuning of constants.•The effect of the bubble Reynolds number is included explicitly.•The present model also considers the increased drag caused by the nearby wall. A two-fluid model based on an Eulerian-Eulerian approach must accurately model interfacial momentum exchange, which includes drag force and shear-induced and wall-induced lift forces. However, the modelling of the wall effect is not yet fully established. Therefore, we propose a new two-fluid closure model for wall effect on drag and lift forces in bubbly flows. The present model is based on resolved simulations of flow over a spherical bubble moving near the wall and fitted correlations for simulated drag and lift coefficients. In the present wall force model, the effect of the bubble Reynolds number is included explicitly in the two-fluid model framework. To validate the present model, numerical simulations are conducted for both laminar and turbulent bubbly flows. As a result, more accurate and reliable results for bubbly flows could be produced by using the present wall model in combination with the shear-induced lift in Tomiyama et al. (2002).