This paper describes the atomization process of a liquid sheet generated by a coaxial swirl injector and it establishes a theoretical breakup model to predict the Sauter mean diameter (SMD) in the entire spray field. The two stage breakup model, which includes Kelvin-Helmholtz (K-H) and Rayleigh-Taylor (R-T) instability, is established and combined with the dispersion relation obtained by linear stability analysis. The theoretical expression to predict the SMD is then determined by full wavelength integration. The validity of the present model is first verified; the results predicted by the theoretical model showed good agreement with previous experimental data. Subsequently, effects of fluid physical properties and flow parameters on the SMD are also investigated. The related conclusions are compared and concur well with the existing literature.

本文描述了由同轴旋流喷射器产生的液片的雾化过程，并建立了一个理论破碎模型来预测整个喷雾场中的 Sauter 平均直径 (SMD)。建立了包含开尔文-亥姆霍兹(KH)和瑞利-泰勒(RT)不稳定性的两阶段破裂模型，并结合线性稳定性分析得到的色散关系。然后通过全波长积分确定预测 SMD 的理论表达式。首先验证本模型的有效性；理论模型预测的结果与先前的实验数据显示出良好的一致性。随后，还研究了流体物理特性和流动参数对 SMD 的影响。相关结论与现有文献进行了比较和吻合。