Application of a new model for bubble-induced turbulence to bubbly flows in containers and vertical pipes


Application of a new model for bubble-induced turbulence to bubbly flows in containers and vertical pipes

Liao, Y.; Ma, T.; Krepper, E.; Lucas, D.; Fröhlich, J.

The present paper extends the baseline model for the CFD-simulation of turbulent poly-disperse bubbly flows in the Euler-Euler framework by improving the modelling of bubble-induced turbulence. The closure terms in the transport equations of the k-ω SST model are revisited and replaced with a new model recently proposed by Ma et al. (Ma et al., Physical Review Fluids 2, 034301, 2017) which is based on an analysis of the turbulent kinetic energy budget obtained from direct numerical simulation data. Detailed validation results for various flow configurations with a wide range of gas and liquid volumetric fluxes are presented. In case of vertical pipe flow significant improvements in the predicted gas volume fraction and velocity profiles are obtained, especially in high gas volume fraction cases where bubble-induced turbulence is dominant. Simulations of other configurations, such as uniform and non-uniform bubble columns, show that the new model results in an also for these cases overall improvement. Therefore, the baseline model is now updated to include the new model for bubble-induced turbulence.

Keywords: Bubbly flow; Bubble-induced turbulence; Euler-Euler modelling; Baseline model

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Publ.-Id: 28589