On the numerical study and characteristic analysis of bubbly flow created by ventilated cavity

Considering the significant influence that the bubbly flow created at the tail of the ventilated cavity makes on the vehicle hydrodynamics and the cavity control mechanism, a Eulerian-Eulerian two-fluid model was proposed for simulation on the bubbly wakes created by ventilated cavity. The population balance approach integrated with Multiple-Size-Group (MUSIG) model was adopted to predict the bubble size distribution. Furthermore, a new model for the turbulence dispersion coefficient was introduced to take into account the effect of void fraction. Based on the simulation model, the characteristics of the multiphase flow field including a vortex mixing area with high void fraction were successfully captured. The bubbles were found to be broken up into small ones right after entrained into the mixing region due to the high turbulence dissipation rate. The void fraction and velocity distribution in the wake were obtained to compare with experimental data. The water velocity in the wake was found to be in accordance with the distribution law in the wake created by single phase flow passing bluff body. The model was validated in predicting the bubbly flow created by ventilated cavity for good agreement with two experimental cases