可压缩气体中的三维黏性液体射流雾化机理

建立了可压缩气体中的三维黏性液体射流雾化数学模型,在射流雾化过程中起控制作用的参数主要有气液速度、气液密度、气液界面表面张力、液体黏性、喷嘴直径及音速.采用线性空间稳定性分析方法详细分析了这些参数在高速射流雾化过程中不稳定性的作用.结果是：增加液体射流速度、气体密度及喷嘴直径;减少液体密度、液体黏性及表面张力,可使射流不稳定性增强.此外,当气流与液体射流反向时增加气体流速也可以使流动不稳定性增强,但当气流与液体射流同向时结果相反.气体可压缩性的增加使流动变得不稳定,但它的影响是很小的.

Atomization Mechanisms of 3-D Viscous Liquid Jets in a Compressible Gas

The mathematic model for 3-dimensional viscous liquid jets in a compressible gas is proposed in this paper. The main parameters governing jet atomization are the velocity and density of gas and liquid, the surface tension, the liquid viscosity, the nozzle diameter and the sound speed. Based on the spatial linear stability analysis, the effects of those parameters on the instability of a high-speed jet are analyzed in details. The study shows that jet instability is enhanced while increasing the liquid velocity, the gas density, and the nozzle diameter and/or reducing the liquid density, the liquid viscosity, and the surface tension. When gas and liquid flow in an opposite direction, an increase in gas velocity will increase the instability of liquid jets. When gas and liquid flow in the same direction, an increase in gas velocity will reduce the instability of liquid jets. The compressibility of the gas tends to increase the jet instability ; however, its impact on atomization of the liquid jets is little.