The paper aims at modeling and simulating the atomization process of the close-coupled ring-hole nozzle in vacuum induction gas atomization (VIGA) for metallic powder production. First of all, the primary atomization of the ring-hole nozzle is simulated by the volume of fluid (VOF) coupled large eddy simulation (LES) model. To simulate the secondary atomization process, we use the method of selecting the droplet sub-model and the VOF model. The results show that the ring-hole nozzle forms a gas recirculation zone at the bottom of the delivery tube, which is the main reason for the formation of an annular liquid film during the primary atomization. In addition, the primary atomization process of the ring-hole nozzle consists of three stages: the formation of the serrated liquid film tip, the appearance and shedding of the ligaments, and the fragmentation of ligaments. At the same time, the primary atomization mainly forms spherical droplets and long droplets, but only the long droplets can be reserved and proceed to the secondary atomization. Moreover, increasing the number of ring holes from 18 to 30, the mass median diameter (MMD, d ₅₀) of the primary atomized droplets decreases first and then increases, which is mainly due to the change of the thickness of the melt film. Moreover, the secondary atomization of the ring-hole nozzles is mainly in bag breakup mode and multimode breakup model, and bag breakup will result in the formation of hollow powder, which can be avoided by increasing the gas velocity.

本文旨在对用于金属粉末生产的真空感应气体雾化（VIGA）中的紧耦合环孔喷嘴的雾化过程进行建模和模拟。首先，通过流体体积（VOF）耦合大涡模拟（LES）模型模拟​​了环孔喷嘴的一次雾化。为了模拟二次雾化过程，我们采用了选择液滴子模型和VOF模型的方法。结果表明，环孔喷嘴在输送管底部形成了气体回流区，这是初级雾化过程中形成环状液膜的主要原因。此外，环孔喷嘴的初级雾化过程包括三个阶段：锯齿状液膜尖端的形成，韧带的出现和脱落，和韧带断裂。同时，一次雾化主要形成球形雾滴和长雾滴，但只能保留长雾滴进行二次雾化。此外，将环孔的数量从 18 个增加到 30 个，质量中值直径 (MMD,d ₅₀ ) 初级雾化液滴先减少后增加，这主要是由于熔膜厚度的变化。此外，环孔喷嘴的二次雾化主要是破袋模式和多模式破袋，破袋会导致形成中空粉末，可以通过提高气速来避免。