The Primary Breakup of a Round Liquid Jet by a Coaxial Flow of Gas

Numerical simulations are conducted to investigate the primary atomization of a round liquid jet surrounded by a coaxial flow of gas. A Refined Level Set Grid (RLSG) method coupled to a Lagrangian spray model is used to capture the whole breakup process of the liquid jet. In the near field of the liquid jet, where the primary breakup occurs, motion and topological changes of the liquid jet are described by the RLSG method. The ligaments are growing from the liquid core and broken into various sizes of drops. The small broken drops are transferred to a Lagrangian stochastic spray model in order to describe the secondary breakup process. The characteristic mechanisms of the jet breakup are consistent with the experimentally observed physical mechanisms and the corresponding stability analysis. The drop-size distribution of the resulting spray is dependent on the grid size for drops smaller than two G-grid cells. Corresponding Author