Numerical Investigations into the Effect of Confinement on the Stability of an Oscillating Planar Liquid Jet

Abstract

Abstract The liquid jet under certain conditions when perturbed will lead to instability. The understanding about an effect of confinement on these jets is still obscure. Hence, numerical investigations are reported in the present study for two phase spatially oscillating planar jet in a quiescent air under the confined conditions. Simulations are performed by solving the Navier-Stokes equations using volume of fluid (VOF) method to track the air-water interface. In the present study an oscillating jet is subjected to various confinement ratios (CR) to understand the jet behaviour under such conditions. It is demonstrated that the amplitude of oscillation increases as the confinement ratio decreases. This behaviour is a result of increased intensity of vortex rotation at each jet peaks as the confinement ratio increases. Moreover, it is also demonstrated that the vortex structure interact with the side-walls and disturb the incoming flow causing non-linear growth of oscillations leading to primary breakup in these jets.