Study of The Fundamental Dynamics of Water Wave Effects on Turbulence for Environmental Applications

本研究的重点是研究Langmuir细胞附近流动结构产生的湍流。它们是成对的大型水平反旋转涡旋，出现在海洋和湖泊中，并与风向和波浪方向对齐。它们在许多环境问题中发挥重要作用，包括海上溢油的运输、大气和海洋之间温室气体的转移以及影响水生生态系统的湖泊的运输和混合过程。提出采用大涡模拟（Large Eddy Simulation， LES）模型，对水面变形连续采用数值网格，捕捉和理解Langmuir胞元的动力学和形成过程。这是对这种流动建模的一个步骤变化，因为目前的模拟和现有的理论，如Craik-Leibovich （C-L）模型，简化了假设平面接口的流动。目标是直接捕捉Langmuir细胞的形成和进化，而不需要（C-L）模型的简化。流场的详细描述将用于研究Langmuir单体湍流波动和涡旋动力学的基本机制，并在此基础上修正和更新C-L理论。这项研究可能会影响我们对石油泄漏在海上的运输，大气和海洋之间温室气体的转移，以及湖泊中影响水生生态系统的运输和混合过程的理解。作为该项目教育范围的一部分，美国土著高中学生将通过参加由PI共同组织的夏令营活动来了解环境流体力学。

PI: Shen, LianProposal Number: 1605080The proposed research is focused on the study of turbulence generated close to the flow structures known as Langmuir cells. These are pairs of large, horizontal counter-rotating vortices that appear in the ocean and in lakes and are aligned in the wind and wave direction. They play an important role in many environmental problems including the transport of oil spills at sea, transfer of greenhouse gases between the atmosphere and oceans, and the transport and mixing processes in lakes that affect aquatic ecosystems. It is proposed to use Large Eddy Simulation (LES) models, where the numerical mesh continuously adopts to the water surface deformation, to capture and understand the dynamics and the process of formation of Langmuir cells. This is a step change in modeling such flows, since current simulations and existing theories, like the Craik-Leibovich (C-L) model, simplify the flow assuming flat interfaces. The goal is to capture the formation and evolution of Langmuir cells directly, without the simplifications of the (C-L) model. Detailed descriptions of the flow field will be used to investigate the fundamental mechanisms of turbulence fluctuations and vortex dynamics in Langmuir cells, based on which the C-L theory will be corrected and updated. This research could impact our understanding of transport of oil spills at sea, transfer of greenhouse gases between the atmosphere and oceans, and the transport and mixing processes in lakes that affect aquatic ecosystems. As part of the educational scope of the project, Native American high school students will be introduced to environmental fluid mechanics through their participation in summer camp activities co-organized by the PI.