Spray dispersion regimes following atomization in a turbulent co-axial gas jet

A canonical co-axial round-jet two-fluid atomizer where atomization occurs over a wide range of momentum ratios: $M=1.9 - 376.4$ is studied. The near field the spray, droplet formation process takes place, characterized and linked to dispersion in far jet. Counterintuitively, our results indicate that low-momentum regime, increasing gas phase leads less dispersion. critical ratio order $M_c=50$ , separates this regime from high-momentum one with dispersion, found both fields. phenomenological model proposed determines susceptibility droplets disperse beyond nominal extent based on Stokes number, $St=\tau _p/T_E=1.9$ formulated local Eulerian large scale eddy turnover time, $T_E$ droplets’ response $\tau _p$ . two-dimensional space summarizes these different regimes context spray characteristics literature.