Determination of the aerodynamic droplet breakup boundaries based on a total force approach

摘要

The determination of the critical We(g) number separating the different breakup regimes has been extensively studied in several experimental and numerical works, while empirical and semi-analytical approaches have been proposed to relate the critical Weg number with the Oh(l) number. Nevertheless, under certain conditions, the Re-g number and the density ratio epsilon may become important. The present work provides a simple but reliable enough methodology to determine the critical We(g) number as a function of the aforementioned parameters in an effort to fill this gap in knowledge. It considers the main forces acting on the droplet (aerodynamic, surface tension and viscous) and provides a general criterion for breakup to occur but also for the transition among the different breakup regimes. In this light, the present work proposes the introduction of a new set of parameters named as We(g),(eff) and Ca-l monitored in a new breakup plane. This plane provides a direct relation between gas inertia and liquid viscosity forces, while the secondary effects of Re-g, number and density ratio have been embedded inside the effective We(g) number (We(g),(eff))