基于流体体积(VoF)界面捕捉方法和剪切应力输运(SST k-ω)湍流模型,通过数值模拟揭示气体雾化制粉工艺中金属熔体在导流管内的流动机理.验证实验表明,数值模型能对导流管内的流体流动过程进行合理预测.随着导流管内径的减小,熔融铝和熔融铁的流动阻力增大,当导流管内径减小至1 mm时,熔体的流动阻力可达102 kPa数量级.基于传统的气体雾化工艺,在金属熔体上方施加正向压力克服熔体在导流管内的流动阻力并在不同导流管内径下雾化高黏性铝合金熔体.当导流管内径从4 mm减小到2 mm时,粉末的细粉收得率(<150μm)从54.7％大幅增加到94.2％.当采用较小内径的导流管时,粉末的表面质量也有所改善.“,”Based on volume of fluid (VoF) interface capturing method and shear-stress transport (SST) k-ω turbulence model, numerical simulation was performed to reveal the flow mechanism of metal melts in melt delivery nozzle (MDN) during gas atomization (GA) process. The experimental validation indicated that the numerical models could give a reasonable prediction on the melt flow process in the MDN. With the decrease of the MDN inner-diameter, the melt flow resistance increased for both molten aluminum and iron, especially achieving an order of 102 kPa in the case of the MDN inner-diameter ≤1 mm. Based on the conventional GA process, the positive pressure was imposed on the viscous aluminum alloy melt to overcome its flow resistance in the MDN, thus producing powders under different MDN inner-diameters. When the MDN inner-diameter was reduced from 4 to 2 mm, the yield of fine powder (<150 μm) soared from 54.7％ to 94.2％. The surface quality of powders has also been improved when using a smaller inner-diameter MDN.