Numerical simulation of three-dimensional transient flow characteristics for a dual-fluid atomizer

This paper aims to study the three-dimensional transient flow-field properties of the gas?liquid dual-fluid atomizer, which has high flow capacity and low energy consumption. The two-phase atomization process of air and water, the negative pressure gradient near the porous medium and the recirculation flow inside the atomizer were numerically simulated and analyzed. Primarily, the influence of the air flow velocity on the water flow velocity at the water inlet was numerically studied. Furthermore, it was proven that the simulated results agree well with the experimental data. Thereafter, the variations in the inlet?s water flow velocity and vortex current zone size were studied in detail with changes in the orifice diameter and outlet pipe length. The results indicated that the water absorption improves as the air flow velocity increases. There is a suitable orifice diameter to maximize water flow and maximize the secondary atomization. The water flow velocity becomes larger and the secondary atomization improves as the length of the outlet pipe increases. The larger the vortex region, the smaller the droplet size. This study could provide theoretical data and guidance for the optimization design of dual-fluid atomizers.