Linear Instability Analysis of Viscous Planar Liquid Sheet Sandwiched Between Two Moving Gas Streams

摘要

Atomization is the process of breaking down of bulk liquid into small droplets due to the action of several forces such as centrifugal, aerodynamic, viscous and surface tension forces. In twin-fluid atomizers, gases are injected at high velocities to further assist the disintegration process of the liquid sheet. Though the effect of viscosity is mostly ignored in instability studies due to high fluid velocity assumption, it may still have a stabilizing or destabilizing effect on the liquid sheet depending upon the flow conditions. The present study performs a linear instability analysis of viscous liquid sheet moving in-between two gas streams of nonzero equal velocities. The effect of gas velocity on maximum growth rate and critical wave number has been presented for a range of gas to liquid density ratios and liquid Weber numbers. While gas velocity has a major destabilizing effect on the liquid sheet, gas density and liquid Weber number mostly influence the critical wave number at low gas velocities.