Experimental Characterization of a Liquid Jet Emanating From An Effervescent Atomizer

Abstract

The study focuses on experimental characterization of the primary atomization associated with an effervescent atomizer. Unlike the existing designs available in the literature that inject air perpendicular to the liquid flow direction, the present atomizer design utilizes coflowing air configuration. In doing so, the aerodynamic shear at the liquid–gas interface create instability and enhance the subsequent jet breakup. Both integrated and intrinsic properties of the liquid jet were extracted by utilizing high-speed flow visualization techniques. The integrated property consists of breakup length, while the intrinsic property involves primary and intermediate breakup frequencies. The primary instability is characterized by low-frequency sinusoidal mode, whereas the intermediate instability consists of high-frequency dilatational mode. Dimensionless plots of these parameters with Weber number ratio leads to a better collapse of data, thereby generating appropriate universal functions. The combined diagram of frequencies converge with increasing relative velocity. This may be due to the dominance of energy consuming sinusoidal wave as the aerodynamic shear increases.