INSTABILITY OF A CONFINED VISCOELASTIC ANNULAR LIQUID LAYER: LINEAR BEHAVIORS AND ENERGY BUDGET

The temporal unstable response of a three-dimensional confined viscoelastic annular liquid layer subjected to an inner swirling gaseous jet, which is a typical flow condition in the coaxial injector, was investigated in the present study. A linear instability analysis was implemented with the Oldroyd-B constitution equation employed. Effects of some flow parameters, including the non-Newtonian rheological properties, the rotating strength, the aerodynamic and capillary behaviors, on sheet instability were fully examined for the axisymmetric and non-axisymmetric disturbance modes. Finally, an energy analysis was carefully conducted to verify the mechanism of the instability predicted by the linear instability analysis.