DETAILED NUMERICAL SIMULATIONS OF ATOMIZATION OF A LIQUID JET IN A SWIRLING GAS CROSSFLOW

Breakup of a liquid jet in a high-speed gaseous cross flow finds wide range of engineering and technological applications, especially in the combustors of the gas turbine engines in the aerospace industry. In this study, we present volume-of-fluid method based direct numerical simulations of a liquid jet injected into a swirling cross flow of gas. The liquid is injected radially outward from a central tube to a confined annular space with a swirling gas cross flow. The essential features of the jet breakup involving jet flattening, surface waves, and stripping of droplets from the edges of the jet are captured in the simulations. We discuss the effect of swirl on the spray characteristics such as jet trajectory; column breakup-length; and size, shape-factor, and velocity distribution of the drops. Drop size increases with swirl and penetration is slightly reduced. Moreover, the trajectory follows an angle (azimuthal) that is smaller than the geometric angle of the swirl at the inlet. Interestingly, we also observe coalescence events downstream of the jet that affect the final droplet size distribution for the geometry considered in this study.