Nonlinear Instability Analysis of an Annular Swirling Viscous Liquid Sheet

Abstract

A nonlinear spatial instability analysis of an annular swirling viscous liquid sheet has been carried out by a perturbation expansion method with the initial amplitude of the disturbance as the perturbation parameter. The viscous liquid sheet is considered to move axially and azimuthally and is exposed to co-flowing inner and outer gas streams. The effects of liquid swirl strength and liquid viscosity on the sheet instability and breakup length have been studied. The results show that except at very low values of swirl to axial velocity ratio of the liquid sheet, the liquid swirl destabilizes the sheet. The sheet breakup length increases slightly and then decreases rapidly with an increase in liquid swirl strength. Viscosity has a stabilizing effect on the sheet breakup. The sheet breakup length increases with an increase in liquid viscosity.