This paper aims at studying the influence mechanism of gas temperatures (300 K, 400 K, 500 K, and 600 K) on gas atomization by simulating the integral atomization process of the close-coupled nozzle in vacuum induction gas atomization (VIGA). The primary atomization is simulated by the volume of fluid (VOF) approach, and the second atomization is studied by the discrete phase model (DPM) combined with the instability breakage model. The results show that, at an increased gas temperature, the influences of gas–liquid contact angle and gas temperature in the recirculation zone on the primary atomization are virtually negligible. However, increasing the gas temperature will increase the gas–liquid relative velocity near the recirculation zone and decrease the melt film thickness, which are the main reasons for the reduced mass median diameter (MMD, d ₅₀) of primary atomized droplets. During the secondary atomization, increasing the gas temperature from 300 K to 600 K results in an increase in the droplet dispersion angle, which is beneficial to the formation of spherical metal powder. In addition, increasing the gas temperature, the positive effect of gas–liquid relative velocity increase on droplets refinement overweighs the negative influence of the GMR decrease, resulting in the reduced MMD and diameter distribution interval. From the analysis of the atomization mechanism, the increase in atomization efficiency caused by increasing the temperature of the atomizing gas, including primary atomization and secondary atomization, is mainly due to the increase in the gas drag force difference between the inner and outer sides of the annular liquid film.

本文旨在通过模拟真空感应气体雾化（VIGA）中紧耦合喷嘴的整体雾化过程，研究气体温度（300 K、400 K、500 K和600 K）对气体雾化的影响机制。初级雾化采用流体体积（VOF）方法模拟，二级雾化采用离散相模型（DPM）结合不稳定性破坏模型进行研究。结果表明，在气体温度升高时，再循环区气液接触角和气体温度对初级雾化的影响几乎可以忽略不计。然而，提高气体温度会增加回流区附近的气液相对速度并降低熔膜厚度，这是质量中值直径（MMD，d ₅₀ ) 的初级雾化液滴。在二次雾化过程中，气体温度从 300 K 增加到 600 K 导致液滴分散角增大，有利于球形金属粉末的形成。此外，增加气体温度，气液相对速度增加对液滴细化的积极影响超过了 GMR 降低的负面影响，导致 MMD 和直径分布区间减小。从雾化机理分析，雾化气体温度升高引起雾化效率的提高，包括初级雾化和二级雾化，主要是由于雾化器内外两侧的气体拖曳力差增大。环形液膜。