University of Monastir, National School of Engineers of Monastir, Laboratory of Metrology and Energy Systems, Monastir, 5000, Tunisia
National Institute of Applied Science Lyon, Laboratory of Fluid Mechanics and Acoustics, 20 Av. A. Einstein, 69621 Villeurbanne Cedex, France
This paper presents a comparative assessment of low Reynolds number k- models against standard k- model in an Eulerian framework. Three different low-Re number k- models: Launder-Sharma (LS), Yang-Shih (YS) and AbeKondoh-Nagano (AKN) have been used for the description of bubble plume behaviour in stratified water. The contribution of the gas phase movement into the liquid phase turbulence has been achieved by using the Dispersed with Bubble Induced Turbulence approach (DIS+BIT).The results reveal that the oscillation frequency of gas-liquid flow are correctly reproduced by standard k- and LS models. In fact, we found for standard K- and LS a clear dominant peak at a frequency equal to 0.1 Hz. On the other hand, YS and AKN models have predicted chaotic oscillations. The oscillation amplitude of the bubble plume predicted from LS model seems to be in good agreement with the PIV measurements of Besbes et al. (2015). However, for the standard K- model the oscillation amplitude is low. The air-water interface shows that the bubble plume mixing with the stratified water is predicted to be stronger compared to standard k- model.