Abstract: Considering the significant influence that the bubblyflow created at the tail of the ventilated cavity makes on the vehiclehydrodynamics and the cavity control mechanism, a Eulerian--Euleriantwo-fluid model was proposed for simulation on the bubbly wakes created byventilated cavity. The population balance approach integrated withMultiple-Size-Group (MUSIG) model was adopted to predict the bubble sizedistribution. Furthermore, a new model for the turbulence dispersioncoefficient was introduced to take into account the effect of void fraction.Based on the simulation model, the characteristics of the multiphase flowfield including a vortex mixing area with high void fraction weresuccessfully captured. The bubbles were found to be broken up into smallones right after entrained into the mixing region due to the high turbulencedissipation rate. The void fraction and velocity distribution in the wakewere obtained to compare with experimental data. The water velocity in thewake was found to be in accordance with the distribution law in the wakecreated by single phase flow passing bluff body. The model was validated inpredicting the bubbly flow created by ventilated cavity for good agreementwith two experimental cases.