Analysis of Vortex Dynamics of Gas-liquid Two-phase Crossflows around a Porous Plate

In order to investigate the vortex structures of multiphase flows around a porous plate, the flow characteristics of gas-liquid two-phase crossflows were numerically simulated by using the RNG k-ε turbulence modeland the Level Set model. The simulated results are compared with the experimental results. The research results show that the separation point and the horseshoe vortex are formed since the crossflow is blocked by gas jet, which can be observed at the upstream of the jet hole. With the increases in the distance away from the wall, the separation point gradually gets close to the jet exit hole. The crossflow detours the jet and forms two counter-rotating vortices on the lateral edges of jet, and the vortex evolution depends upon the distance away from the wall. The counter-rotating vortex pairs (CVP) are formed in the jet region. The development process of the vortex pairs can be devided into 3 stages: in the near wake-region (i.e., close to the edge of the jet exit hole), the counter-rotating vortex pairs gradually form on the wall, and the increases in the heights of the vortex cores ae well as the distance between the cores lead to the expansion of vortex area. As the flow develops toward downstream, the area of CVP shrinks and even disappears entirely. Further downstream, the CVP appears again on the top of the jet corresponding to the formation of secondary vortex pairs in the near-wall region.