Collaborative Research: Improved observation and parameterization of bottom boundary layer turbulence and particle properties for sediment fate and transport modeling

合作研究：改进底部边界层湍流和颗粒特性的观测和参数化，以进行沉积物归宿和输运建模

基本信息

批准号：
1736668
负责人：
Oliver Fringer
金额：
$ 137.59万
依托单位：
Stanford University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-15 至 2022-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736668&HistoricalAwards=false
关键词：
Collaborative Research Improved observation parameterization

项目摘要

Sediment fate and transport models are often utilized to help address environmental questions related to the environmental impacts of remediation efforts, the potential for reliable natural recovery, and the potential impacts of extreme events. In order to effectively implement sediment fate and transport models, bed erosion and deposition rates must be accurately parameterized. These processes are dependent on physical forcing, the distribution of sediment in the water column, and the properties of sediment such as bulk density, particle size, and biogeochemical composition. This research will employ high-resolution numerical simulations along with analysis of in-situ measurements of physical processes and particle characteristics to quantify turbulent forcing and particle properties affecting sediment resuspension, settling, and flocculation. The project links academic-level researchers directly with practitioners actively involved with several USEPA Superfund sites and indirectly with environmental researchers, engineers, and policy makers. The project will support the Ph.D. research of two graduate students who will be advised by a diverse group and trained in advanced computational fluid dynamics, acoustic and optical field instrumentation, as well as practical aspects of environmental engineering. Results from this study will link methods and results from academic research to practice, enabling application of novel methods for quantifying and predicting sediment and contaminant fate and transport to present-day contaminated sediment sites. Additionally, the PIs have worked extensively with community modeling efforts and have contributed sediment transport modules to the Environmental Fluid Dynamics Code (EFDC), a state-of-the-art hydrodynamic model in use by the USEPA. In this project, novel in-situ acoustical and optical instrument platforms will be deployed and laboratory experiments will be conducted to measure the physio-biogeochemical characteristics of flow and sediment in a turbulent, current and wave-driven shallow estuarine setting. Acoustic instrumentation will measure vertical distributions of mean flows and turbulence throughout the water column, including within the boundary layer, due to currents and waves. These will be combined with a floc camera and optical instruments that measure settling flux, particle size distributions and particulate biogeochemical compositions. Laboratory experiments will measure erosion rates and bulk densities of in-situ sediment cores. The field and laboratory observations of the sediment characteristics will be used to inform a high resolution large-eddy simulation (LES) model that resolves the details of the turbulent, sediment-laden boundary layer. The suite of data obtained from the field observations, laboratory experiments, and LES model will be used to understand the relationship between particle size distributions and turbulence in wave-driven estuarine environments and how these dynamics are affected by biogeochemical properties of the suspended particles. These dynamics will in turn be related to properties of the bed to understand how the turbulence and particle size distributions affect erosion rates. Finally, the LES model will be used to understand flocculation dynamics and the effects of sediment-induced stratification that may act to dampen the near-bed turbulence and reduce subsequent erosion and entrainment of sediment into the water column.

沉积物归宿和迁移模型通常用于帮助解决与修复工作的环境影响、可靠自然恢复的潜力以及极端事件的潜在影响相关的环境问题。为了有效地实施沉积物归宿和迁移模型，必须准确地参数化河床侵蚀和沉积速率。这些过程取决于物理强迫、沉积物在水柱中的分布以及沉积物的特性，例如堆积密度、颗粒尺寸和生物地球化学成分。这项研究将采用高分辨率数值模拟以及对物理过程和颗粒特征的现场测量分析，以量化影响沉积物再悬浮、沉降和絮凝的湍流强迫和颗粒特性。该项目将学术级研究人员直接与积极参与多个 USEPA 超级基金站点的从业者联系起来，并间接与环境研究人员、工程师和政策制定者联系起来。该项目将支持博士学位。两名研究生的研究将由不同的小组提供建议，并接受高级计算流体动力学、声学和光学领域仪器以及环境工程实践方面的培训。这项研究的结果将把学术研究的方法和结果与实践联系起来，从而能够应用新方法来量化和预测沉积物和污染物的命运以及向当今受污染的沉积物地点的运输。此外，PI 还广泛参与社区建模工作，并为环境流体动力学规范 (EFDC) 贡献了沉积物传输模块，EFDC 是 USEPA 使用的最先进的流体动力学模型。在该项目中，将部署新型原位声学和光学仪器平台，并进行实验室实验，以测量湍流、水流和波浪驱动的浅河口环境中水流和沉积物的物理生物地球化学特征。声学仪器将测量整个水体（包括边界层内）由于水流和波浪而产生的平均流量和湍流的垂直分布。这些将与絮凝相机和光学仪器相结合，测量沉降通量、粒度分布和颗粒生物地球化学成分。实验室实验将测量原位沉积物岩心的侵蚀率和堆积密度。沉积物特征的现场和实验室观察将用于为高分辨率大涡模拟（LES）模型提供信息，该模型可解析湍流、充满沉积物的边界层的细节。从现场观测、实验室实验和 LES 模型获得的一系列数据将用于了解波浪驱动的河口环境中颗粒尺寸分布和湍流之间的关系，以及这些动力学如何受到悬浮颗粒的生物地球化学特性的影响。这些动力学反过来又与床的特性相关，以了解湍流和颗粒尺寸分布如何影响侵蚀率。最后，LES 模型将用于了解絮凝动力学和沉积物引起的分层的影响，其可能起到抑制近床湍流并减少随后的侵蚀和沉积物夹带到水柱中的作用。

项目成果

期刊论文数量（11）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

On the Variability of Floc Characteristics in a Shallow Estuary

浅水河口絮体特性的变异性研究

DOI：
10.1029/2021jc018343
发表时间：
2022-06
期刊：
Journal of Geophysical Research: Oceans
影响因子：
0
作者：
Egan, Galen;Chang, Grace;Manning, Andrew J.;Monismith, Stephen;Fringer, Oliver
通讯作者：
Fringer, Oliver

Cohesive Sediment Erosion in a Combined Wave‐Current Boundary Layer

组合波中的粘性沉积物侵蚀——当前边界层

DOI：
10.1029/2020jc016655
发表时间：
2021-02
期刊：
Journal of Geophysical Research: Oceans
影响因子：
0
作者：
Egan, Galen;Chang, Grace;McWilliams, Samuel;Revelas, Gene;Fringer, Oliver;Monismith, Stephen
通讯作者：
Monismith, Stephen

Seasonal particle responses to near‐bed shear stress in a shallow, wave‐ and current‐driven environment

在浅海、波浪和海流驱动的环境中，季节性颗粒对近床剪切应力的响应

DOI：
10.1002/lol2.10221
发表时间：
2021-11-02
期刊：
Limnology and Oceanography Letters
影响因子：
7.8
作者：
G. Chang;Galen Egan;J. McNeil;S. McWilliams;Craig Jones;F. Spada;S. Monismith;O. Fringer
通讯作者：
O. Fringer

Quantification of 3-dimensional structure and properties of flocculated natural suspended sediment

絮凝天然悬浮沉积物的三维结构和性质的量化

DOI：
10.1016/j.watres.2022.118835
发表时间：
2022-08
期刊：
Water Research
影响因子：
12.8
作者：
Spencer, K.L.;Wheatland, J.A.;Carr, S.J.;Manning, A.J.;Bushby, A.J.;Gu, C.;Botto, L.;Lawrence, T.
通讯作者：
Lawrence, T.

Sediment‐Induced Stratification in an Estuarine Bottom Boundary Layer

沉积物——河口底部边界层中引起的分层