Bubble-induced turbulence in CFD simulation of bubble columns. Part I: Coupling of SIT and BIT

Abstract

One of the challenges in CFD simulation of gas–liquid flow is the modeling of shear-induced turbulence (SIT) and bubble-induced turbulence (BIT). Although many BIT models have been proposed, there is no consensus on the effect of BIT models. This paper aims to investigate this issue and the coupling mechanisms of SIT and BIT. When activating BIT, we find a marginal effect of Simonin model, yet a significant effect of the Sato or TH model. In addition, the coupling mechanisms of BIT and SIT are different when applying various SIT models. For the RNG k-ε model, the Sato model generates a snowball effect that greatly increases the SIT viscosity, but this effect is lacking in the standard k-ε model. In summary, the role of BIT in CFD simulation depends on its formulation and the coupling mechanisms with various SIT models. These findings would be helpful to the future study of BIT.