Study of the instability of the annular liquid sheet exiting from the effervescent atomizer at high aeration ratios

In many atomizers, the breakup of the annular liquid sheet exiting from the atomizer is responsible for the formation of the spray and the determination of the spray characteristics. This paper studies the instability of the annular liquid sheet exiting from the effervescent atomizer at high gas to liquid mass flow ratios, in order to better understand the primary breakup process in this type of atomizer. Therefore, the dispersion equation obtained from the 3D linear stability analysis has been solved for the flow conditions of the annular liquid sheet exiting from the effervescent atomizer at 0.38 L/min liquid flow rate and high aeration ratios of 1.24% and 1.84%. The results showed that in the aerated ratios studied, the axisymmetric para-sinusoidal perturbation modes are the predominant in the breakup of the annular liquid sheet. In addition, it was observed that with increasing aeration ratio, the liquid sheet will breakup at shorter wave lengths. Also, the results of the study of the effect of viscosity on the instability of the annular liquid sheet showed that the viscosity of the liquid has some stabilizing effects and non-viscose assumption of the liquid at high aeration ratios can cause errors in calculations of the stability of the annular sheet breakup and the breakup length.