Collaborative Research: Droplet transport in the vicinity of breaking waves: Experiments and simulations

合作研究：破碎波附近的液滴传输：实验和模拟

基本信息

批准号：
1829660
负责人：
Fabrice Veron
金额：
$ 49.41万
依托单位：
University of Delaware
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-10-01 至 2023-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1829660&HistoricalAwards=false
关键词：
Collaborative Research Droplet transport vicinity

项目摘要

The accurate prediction of spray and aerosol generation at the ocean surface is essential for a wide variety of applications including weather and climate predictions. This research aims at characterizing and quantifying droplet transport in the turbulent airflow around breaking surface waves in the ocean. A unique combined experimental and numerical approach is designed. At the air-sea interaction laboratory at the University of Delaware, controlled, repeatable breaking wave events will be re-produced, and measurements of droplet concentration and velocity for different droplet sizes will be used to directly estimate production fluxes. At the University of Notre Dame, measured waveforms and droplet production rates are used as inputs into large eddy simulations configured to recreate laboratory conditions. Droplet statistics are directly compared between experiments and simulations, and the simulations will provide a means for investigating momentum and thermodynamic exchange rates, as well as upscaling to field conditions. Numerical weather and climate models require accurate parameterizations of marine aerosol source fluxes, and only by understanding droplet transport immediately after production can these be faithfully improved. The results of this study will be used for training 2 PhD students and for engaging undergraduate students in STEM disciplines. The results will also be disseminated to a wide audience through the utilization of the research material for educational outreach efforts, including visualizations.The project provides an unprecedented view of droplet dynamics in the turbulent wave boundary layer. Virtually all field observations of spray production rates infer fluxes based on fixed-height concentrations, and this process requires making assumptions regarding the turbulent transport of droplets in the lowest regions of the marine boundary layer. For small droplets, many of these assumptions hold, but for large droplets - those with the largest potential for altering air-sea heat and momentum fluxes - factors such as droplet inertia, flow separation behind breaking waves, and preferred wave-relative ejection locations likely violate assumptions. The research plan is aimed at several specific objectives: (i) performing controlled laboratory experiments which inform numerical simulations, and making one-to-one comparisons of statistics and bulk balances; (ii) directly compute size-resolved vertical fluxes of droplets in both experiments and simulations, in order to reveal the influence of inhomogeneous and intermittent turbulence in the vicinity of surface waves; and (iii) determine the production/deposition velocity of droplets and expand to realistic conditions using the large eddy simulations. The key outcomes will include modified flux-profile relationships of droplets of varying size, and better-informed estimates of spray-induced fluxes of heat, momentum, and moisture.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

准确预测海洋表面喷雾和气溶胶的产生对于包括天气和气候预测在内的各种应用至关重要。这项研究旨在表征和量化海洋破碎表面波周围湍流气流中的液滴传输。设计了一种独特的实验和数值相结合的方法。在特拉华大学的海气相互作用实验室，将重现受控的、可重复的碎波事件，并且对不同液滴尺寸的液滴浓度和速度的测量将用于直接估计生产通量。在圣母大学，测量的波形和液滴生成速率被用作大涡流模拟的输入，该模拟配置用于重建实验室条件。实验和模拟之间直接比较液滴统计数据，模拟将为研究动量和热力学交换率以及放大到现场条件提供一种手段。数值天气和气候模型需要对海洋气溶胶源通量进行准确的参数化，只有在产生后立即了解液滴传输才能真正改进这些模型。这项研究的结果将用于培训 2 名博士生，并让本科生参与 STEM 学科。研究结果还将通过利用研究材料进行教育推广工作（包括可视化）向广大受众传播。该项目提供了湍流波边界层中液滴动力学的前所未有的视图。事实上，所有喷雾生产率的现场观测都是基于固定高度浓度推断通量，并且该过程需要对海洋边界层最低区域中液滴的湍流传输做出假设。对于小液滴，许多这些假设成立，但对于大液滴 - 那些最有可能改变空气-海洋热量和动量通量的液滴 - 诸如液滴惯性、碎波后面的流动分离以及优选的波相对喷射位置等因素可能违反假设。该研究计划旨在实现几个具体目标：（i）进行受控实验室实验，为数值模拟提供信息，并对统计数据和体积平衡进行一对一比较； (ii) 在实验和模拟中直接计算液滴的尺寸分辨垂直通量，以揭示表面波附近不均匀和间歇性湍流的影响； (iii) 确定液滴的产生/沉积速度并使用大涡模拟扩展到实际条件。主要成果将包括修改不同尺寸液滴的通量分布关系，以及对喷雾引起的热量、动量和湿度通量进行更明智的估计。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Three‐Dimensional Measurements of Air Entrainment and Enhanced Bubble Transport During Wave Breaking

波浪破碎过程中空气夹带和增强气泡传输的三维测量

DOI：
10.1029/2022gl099436
发表时间：
2022
期刊：
Geophysical Research Letters
影响因子：
5.2
作者：
Ruth, Daniel J.;Néel, Baptiste;Erinin, Martin A.;Mazzatenta, Megan;Jaquette, Robert;Veron, Fabrice;Deike, Luc
通讯作者：
Deike, Luc

An Eulerian model for sea spray transport and evaporation

海雾传输和蒸发的欧拉模型