A direct modeling approach to momentum, heat and mass exchange at the ocean-atmosphere interface at high wind speed

高风速下海洋-大气界面动量、热量和质量交换的直接建模方法

• 批准号: 2318816
• 负责人: Luc Deike
• 金额: $ 84.47万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2318816&HistoricalAwards=false
• 关键词: direct; modeling; approach; momentum; heat

A better understanding of exchange of momentum, heat, and mass at the ocean-atmosphere interface at very high wind speed is necessary to better predict extreme weather events, which have dramatic impact on human activities, such as tropical cyclone intensification. Given the complexity of these two-phase turbulent flows, modeling tools are extremely valuable to unravel the detailed physical mechanisms. This research will provide a novel computational framework for fully coupled air-water simulations at high wind speed, including breaking waves, turbulent wind, droplet generation and their influence on the heat and mass exchange in the turbulent wave boundary layer. The initial work on the small-scale dynamics of individual breaking waves and droplet evolution will feed into a larger-scale model able to resolve the flows that provide the forcing context for the small-scale model. This comprehensive approach will lead to a general improvement in simplified models and parameterization, that can be implemented and tested in a wide range of numerical tools, from high resolution models to larger scale Earth system models, leading to improvement in climate and weather forecast. This project will expose undergraduate and graduate students at Princeton to critical environmental challenges that require research on fundamental multi-phase flows, and promote the use of open-source methods, through workshop and teaching activities.The large range of scales involved in air-sea interaction will be split into two sets of more tractable problems. The first will consider droplet evaporation in the air, fully resolving droplet ejection and heat exchange with the surrounding air for wind-wave breaking dynamics forced by turbulent boundary layer. Such high-fidelity simulations will span scales from 100 microns to 1m and focus on understanding the small-scale coupling between high wind forced turbulence close to the water surface and droplets, directly solving for heat and mass exchange, waves and droplets processes and the coupling of heat and momentum exchange at high wind speed. The models developed for these small-scale processes will be integrated into a multi-layer numerical framework, akin to large eddy simulations. Such simulations will be able to resolve realistic breaking wave statistics spanning scales from 1m to 1km, allowing to represent the outer scales of the turbulent flow. Analysis of the heat and momentum budget will help understand current uncertainties in bulk formulation and may lead to new parameterizations for the heat and drag coefficient applicable to larger scale models used for tropical cyclone intensification studies.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.

为了更好地预测热带气旋强化等对人类活动产生巨大影响的极端天气事件，有必要更好地了解极高风速下海洋-大气界面处的动量、热量和质量交换。考虑到这些两相湍流的复杂性，建模工具对于阐明详细的物理机制非常有价值。这项研究将为高风速下的全耦合空气-水模拟提供一种新颖的计算框架，包括破碎波、湍流风、液滴生成及其对湍流波边界层中热质交换的影响。关于单个破碎波和液滴演化的小尺度动力学的初步工作将输入到一个更大规模的模型中，该模型能够解析为小尺度模型提供强迫背景的流动。这种综合方法将导致简化模型和参数化的全面改进，可以在从高分辨率模型到更大规模的地球系统模型的各种数值工具中实施和测试，从而改善气候和天气预报。该项目将使普林斯顿大学的本科生和研究生面临严峻的环境挑战，这些挑战需要对基本多相流进行研究，并通过研讨会和教学活动促进开源方法的使用。交互将分为两组更容易处理的问题。第一个将考虑空气中的液滴蒸发，完全解决液滴喷射以及与周围空气的热交换，以实现湍流边界层强制的风波破碎动力学。这种高保真模拟将跨越100微米到1m的尺度，重点了解靠近水面的强风强迫湍流与液滴之间的小尺度耦合，直接求解热质交换、波与液滴过程及其耦合高风速下的热量和动量交换。为这些小规模过程开发的模型将被集成到多层数值框架中，类似于大涡流模拟。此类模拟将能够解析 1m 至 1km 尺度的真实破碎波统计数据，从而能够表示湍流的外部尺度。对热量和动量预算的分析将有助于了解当前散装配方中的不确定性，并可能导致适用于热带气旋强化研究的更大规模模型的热量和阻力系数的新参数化。该奖项反映了 NSF 的法定使命，并被认为是值得的通过使用基金会的智力优势和更广泛的影响审查标准进行评估来获得支持。