Oil dispersion under a deep-water plunging breaker of height 0.15 m was studied by coupling the Lagrangian particle tracking code (NEMO3D) with the population balance model (VDROP). The wave hydrodynamics obtained in Part I (Cui et al. in Environ Fluid Mech 2020 (in press)) was used as input. It was observed that droplet inertia and major forces on droplets significantly impacted the transport of oil droplets under wave conditions, and neglecting it caused less entrainment into the water column and horizontal spread of oil plume. For droplets less than 400 microns, the droplet size distribution (DSD) tended to follow a power-law distribution with an exponent close to − 2.3, which was consistent with earlier experimental observations by Delvigne and Sweeney (Oil Chem Pollut 4(4):281–310, 1988). The distribution of large size droplets evolved with time and showed agreement with a power-law distribution having an exponent of − 9.7 about 20 s after the passage of the wave train. Reducing the interfacial tension enhanced droplets breakup and increased the exponent of power-law distribution to − 6.1 for droplets smaller than 400 microns. It was also found that neglecting the vertical gradient of eddy diffusivity led to the accumulation of oil droplets in low eddy diffusivity regions at the bottom part of the wave breaker. The investigation herein could be used to obtain design values for breakers that could be used in oil spill models to predict the oil droplet size distribution.

通过将拉格朗日粒子跟踪代码（NEMO3D）与种群平衡模型（VDROP）耦合，研究了高度为0.15 m的深水浸入式破碎器下的油分散。第一部分（Cui等人在《 Environ Fluid Mech 2020》（印刷中）中获得）的波浪流体动力学被用作输入。观察到，在波浪条件下，液滴的惯性和作用在液滴上的主要力显着影响了油滴的传输，而忽略它会导致较少的夹带进入水柱和油羽的水平扩散。对于小于400微米的液滴，液滴尺寸分布（DSD）倾向于遵循幂律分布，指数接近-2.3，这与Delvigne和Sweeney的早期实验观察一致（Oil Chem Pollut 4（4）： 281–310，1988年）。大直径液滴的分布随时间发展，并在波列通过后约20 s内与幂律分布一致，指数为-9.7。减小界面张力可增强液滴破裂，并将小于400微米的液滴的幂律分布指数提高至-6.1。还发现，忽略涡流扩散率的垂直梯度会导致油滴在波浪破碎机底部的低涡流扩散率区域中积聚。本文的研究可用于获得断路器的设计值，该断路器可在溢油模型中用于预测油滴大小分布。减小界面张力可增强液滴破裂，并将小于400微米的液滴的幂律分布指数提高至-6.1。还发现，忽略涡流扩散率的垂直梯度会导致油滴在波浪破碎机底部的低涡流扩散率区域中积聚。本文的研究可用于获得断路器的设计值，该断路器可在溢油模型中用于预测油滴大小分布。减小界面张力可增强液滴破裂，并将小于400微米的液滴的幂律分布指数提高至-6.1。还发现，忽略涡流扩散率的垂直梯度会导致油滴在波浪破碎机底部的低涡流扩散率区域中积聚。本文的研究可用于获得断路器的设计值，该断路器可在溢油模型中用于预测油滴大小分布。