Three-dimensional numerical simulation of axis-switching and micro-droplet formation in a co-flowing immiscible elliptic jet flow system using front tracking method

Abstract

In this paper, co-flowing immiscible elliptic jet flow system is investigated numerically in dripping and jetting regimes using front tracking method. In these regimes, the elliptic jet is more unstable than the circular jet. In the jetting regime, the axis-switching of an elliptic liquid jet is studied numerically using front tracking method. The effect of dimensionless parameters like viscosity ratio, density ratio, Weber number, the inner Reynolds number on axis-switching parameters such as maximum jet diameter, mean jet diameter and initial wavelength is considered. The results show that the density ratio affects the initial wavelength more compared to maximum jet diameter. Increasing the viscosity ratio leads to a rise in the maximum jet diameter and a reduction in the initial wavelength. In the dripping regime, the drop formation for elliptic jets is studied, and the results are compared with experiments for elliptic jets. The effect of Weber number of the inner flow, capillary number of the outer flow, viscosity ratio and density ratio on the size of drops formed are studied. It is observed that the microdroplets formed in an elliptic jet are smaller in size compared to a circular jet.