中文摘要：

为探究初始雾化破碎情况,采用数值模拟的方法,结合龙卷风形成原理对金属熔体初始雾化进行理论分析,模拟不同流动形式以及气液比的初始雾化过程。结果表明：与无旋转流动形式相比,旋转流场涡旋作用更容易使熔体形成液膜,气体利用率高;在相同熔体流量下,存在临界气体质量流量0.003 8 kg/s,使液流由喷泉式破碎突变成经典的伞状液膜破碎形式。

英文摘要：

The primary breakup mechanism was investigated by numerical simulation combined with the formation theory of tomado. The effect of air/liquid mass flow rate and gas flow field form including rotational and irrotational flow on the primary atomization were discussed. The results show that using the swirling flow field form is benefits to the formation of a thin melt sheet at the nozzle tip with a higher effective using rate of gas. The primary breakup model which forms a miniature ＂fountain＂ at the nozzle tip abruptly shifts to melt sheet breakup model when the critical flow rate is 0.003 8 kg/s.