Numerical simulation of bag-mode breakup of droplets: Insight into hole formation and droplet size distribution

In this study, we perform three-dimensional Direct Numerical Simulations of the bag film breakup of drops in uniform air flows. A mesh convergence study is conducted with a focus on the consistency of the location where the film first ruptures. We investigate the impact of the gas Reynolds number on the droplet breakup. Additionally, we compare droplet statistics from simulations with experimental results and those obtained using the Manifold Death (MD) algorithm, a numerical method for artificially perforating thin liquid films. The impact of the gas dynamics on the breakup of the liquid film is investigated. Throughout the studies we consistently observed crater formation and a localized pressure jump inside the liquid film at the position where the perforation will develop in later time. Morphological changes of deforming droplets are analyzed and compared for all the cases.