Authors

Abstract

A linear instability analysis of an annular liquid sheet emanating from an atomizer subjected to inner and outer air streams to investigate the liquid viscosity and swirl velocity on the maximum growth rate has been carried out. The dimensionless dispersion equation that governs the instability of a viscous annular liquid sheet under air streams was derived with linear stability analysis. The dispersion equation solved by numerical method and investigated viscosity and swirl velocity effect on maximum growth rate and its corresponding unstable wave number. The results show that decrease in viscosity has positive effect on maximum growth rate and its corresponding unstable wave number. At low liquid swirl Weber number liquid swirl has a stabilizing effect and at high liquid swirl Weber number liquid swirl velocity has a destabilizing effect on the liquid sheet. The growth rate can be related to the breakup length of the liquid sheet and when the growth rate increase, breakup length was shorter. The drop diameter dependent to the wave number and decrease with increase on it that afford to improvement the combustion and decrease the specific fuel consumption.

Keywords

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