Effects of Asymmetric Gas Distribution on the Instability of a Plane Power-Law Liquid Jet

Abstract

As a kind of non-Newtonian fluid with special rheological features, the study of the breakup of power-law liquid jets has drawn more interest due to its extensive engineering applications. This paper investigated the effect of gas media confinement and asymmetry on the instability of power-law plane jets by linear instability analysis. The gas asymmetric conditions mainly result from unequal gas media thickness and aerodynamic forces on both sides of a liquid jet. The results show a limited gas space will strengthen the interaction between gas and liquid and destabilize the power-law liquid jet. Power-law fluid is easier to disintegrate into droplets in asymmetric gas medium than that in the symmetric case. The aerodynamic asymmetry destabilizes para-sinuous mode, whereas stabilizes para-varicose mode. For a large Weber number, the aerodynamic asymmetry plays a more significant role on jet instability compared with boundary asymmetry. The para-sinuous mode is always responsible for the jet breakup in the asymmetric gas media. With a larger gas density or higher liquid velocity, the aerodynamic asymmetry could dramatically promote liquid disintegration. Finally, the influence of two asymmetry distributions on the unstable range was analyzed and the critical curves were obtained to distinguish unstable regimes and stable regimes.

Investigation of the primary breakup length and instability of non-Newtonian viscoelastic liquid jets

“…While Newtonian jets appear rigid, non-Newtonian jets have the additional freedom for elastic deformation. Other authors have also reported similar results [20][21][22].…”

“…where is the liquid normal stress, , is the gas normal stress, and is the pressure induced by the surface tension and it can be expressed as Equation (22).…”