Single Rising Bubble – COMSOL and Fluent Comparison.

0521854 - ÚCHP 2020 DE eng A - Abstract
Crha, Jakub - Basařová, P. - Růžička, Marek
Single Rising Bubble – COMSOL and Fluent Comparison.
Book of Abstracts. -: -, 2019. ISBN N.
[Multiphase Flow Workshop - Conference and Short Course /17./. 11.11.2019-15.11.2019, Dresden]
R&D Projects: GA ČR(CZ) GA19-09518S
Institutional support: RVO:67985858
Keywords : bubble * CFD * multiphase
OECD category: Chemical engineering (plants, products)

The aim of this study is to determine the terminal velocities of a single spherical bubble rising in stagnant pure liquid using different commercial CFD solvers. A case of a single rising bubble serves as a benchmark case to compare the accuracy of different CFD solvers before creating simulations of more complex phenomena. In this study, two commercial solvers were used: COMSOL Multiphysics 5.3 and Ansys Fluent. A 2D axisymmetric simulation of an air bubble (diameter 0.6, 0.8 and 1.5 mm) rising in pure water or in pure propanol was created. Simulation using COMSOL gave better results than simulations in Ansys Fluent. Terminal velocities for 0.6 and 0.8 mm bubbles obtained using COMSOL corresponded very well with theoretical and experimental velocities. The terminal velocity of the largest bubble from COMSOL simulation was underestimated, as the bubble deformation differed from the experimental and theoretical value. Results from Fluent simulation for bubbles of 0.6 and 0.8 mm diameters were not obtained, as the simulation failed due to so-called parasitic currents which occurred during the simulation. Shape deformation and terminal velocity of 1.5 mm bubble obtained from Fluent were underestimated. The results of the simulations are shown in Figure 1.
Permanent Link: http://hdl.handle.net/11104/0306424