Droplet and bubble breakup phenomena under turbulent flow have been widely studied for over 70 years through theoretical, experimental and numerical approaches. Despite significant progress, the dynamics of breakup remains an active research topic. The present study considers a database of breakup events under turbulent conditions. The database contains neutrally buoyant droplets obtained for a single moderate turbulent Reynolds number and a Weber number near the critical Weber number of the droplets, allowing for long time evolution prior to droplet breakage. Each droplet in the database follows a consistent behavior: the droplet undergoes (1) an initial shape deformation, then (2) an extended oscillatory regime, until (3) a critical large deformation starts, leading to (4) a capillary-driven breakup. While the first two stages have been investigated in our previous work using spherical harmonics decomposition, this study focuses on the last two stages, describing them qualitatively and quantitatively by means of seven different shape parameters. These shape parameters are based on different information of the specific droplet such as its surface, its volume or its averaged mean curvature, and provide a multidimensional analysis of the droplet breakup. They are used to measure the time spent in the final two stages prior to breakup, as well as the transition between these stages. Additionally, we establish breakup thresholds for each shape parameter to predict neutrally buoyant droplet breakup under turbulent flow conditions.

70 多年来，人们通过理论、实验和数值方法对湍流下的液滴和气泡破裂现象进行了广泛研究。尽管取得了重大进展，分手的动态仍然是一个活跃的研究课题。本研究考虑了动荡条件下分手事件的数据库。该数据库包含针对单个中等湍流雷诺数和接近液滴临界韦伯数的韦伯数获得的中性浮力液滴，允许在液滴破裂之前进行长时间演化。数据库中的每个液滴都遵循一致的行为：液滴经历（1）初始形状变形，然后（2）扩展振荡状态，直到（3）开始临界大变形，导致（4）毛细管驱动的破裂。虽然我们之前的工作中使用球谐分解研究了前两个阶段，但本研究重点关注最后两个阶段，通过七个不同的形状参数定性和定量地描述它们。这些形状参数基于特定液滴的不同信息，例如其表面、体积或其平均曲率，并提供液滴破碎的多维分析。它们用于衡量分手前最后两个阶段所花费的时间，以及这些阶段之间的过渡。此外，我们为每个形状参数建立了破碎阈值，以预测湍流条件下的中性浮力液滴破碎。