An Enhanced Predictive Method for Large Droplet Breakage Based on the Discrete Particle Model

Abstract

In high-speed flows, a single droplet undergoes fragmentation, yielding numerous child droplets. Conventional breakup models usually group these droplets into a single parcel, neglecting the postbreakup spatial distribution. To address this limitation, detailed numerical simulations have been conducted focusing on the bag and bag–stamen breakup modes of 200 μm-diameter droplet at Weber numbers of 15 and 30. The result shows that the largest length of the child-droplets cloud can reach up to 29 times the original diameter. Importantly, if the grid size is less than 29 times the droplet diameter, traditional models that use a single parcel for child droplets could produce inaccurate results. To overcome this limitation, a disk-like breakup (DLB) model was introduced. With this model, multiple parcels replace the original droplet and are initialized on a virtual disk. Additionally, partitioned breakup modeling was employed for both bag and bag–stamen breakups. Calculations using the DLB model were compared with the Taylor analogy breakup (TAB), Kelvin–Helmholtz Rayleigh–Taylor (KH–RT), and enhanced Taylor analogy breakup (ETAB) models. The result indicates that the DLB model is capable of simulating the spatial distribution of the droplet cloud postbreakup, achieving better agreement with the detailed numerical simulations using the volume of fluid (VOF) method in this paper and experiments in the literature.