Transport in Turbulent Boundary Layers over Permeable Beds: Pore-resolved Direct Simulations and Macroscale Continuum Modeling

渗透层上湍流边界层的传输：孔隙分辨直接模拟和宏观连续体建模

• 批准号: 2053248
• 负责人: Sourabh Apte
• 金额: $ 35.04万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2053248&HistoricalAwards=false
• 关键词: Transport; Turbulent; Boundary; Layers; over

Transient storage, characterized by retention and transport of solutes such as chemicals and pollutants, organic matter, dissolved oxygen, nutrients, and heat across the stream-gravel interface, is one of the most critical concepts in stream ecology with enormous societal value in predicting source of fresh drinking water, nutrient cycling, and sustaining diverse aquatic ecosystems. Lack of an accurate modeling approach that accounts for complex flow physics of turbulence over a permeable bed and coupled transport across the sediment-water interface is one of the key challenges in practical scale modeling of natural aqueous systems. Typical grain-to-globe prediction models of solute transport are sequential in nature and neglect the direct coupling between turbulent stream flow over a permeable bed and groundwater flow within the bed. It is hypothesized that turbulence at the sediment-water interface can significantly alter the transient storage and solute retention times within the gravel beds. Specifically, the structure and dynamics of turbulence over a porous bed can be very different than that over an impermeable, rough wall. Quantifying the upwelling and downwelling events at the stream-bed interface and their modulation by the free-stream turbulence, as well as penetration depth of turbulence structures within the porous bed is critical for the development of macroscale, continuum-based modeling of solute transport. This interdisciplinary research will train two PhD students on direct and large-eddy simulations, volume-averaging techniques, and multiscale analysis. Fundamental numerical experiments are proposed on turbulent boundary layers over permeable gravel beds representative of stream or river flows. Pore-resolved, direct numerical simulations (DNS), using a solver based on the fictitious domain method developed by the PI, of turbulent flow over stationary, porous beds will be conducted for representative flows in natural streams or rivers. The turbulent flow physics for a range of permeability Reynolds numbers for mono and polydispersed, randomly packed gravel beds will be investigated and contrasted against that over rough, impermeable wall with similar topology. The detailed, spatiotemporal pressure and velocity fluctuation data at the interface will be used to develop and validate macroscale, continuum models with variable porosity for large-eddy simulation (LES). The proposed research has the potential to transform the current state-of-the art reach-scale modeling approaches for solute transport used in river management. The pore-resolved DNS data will be used to design a learning module for a graduate level course on `Turbulence Modeling' with a priori and a posteriori analyses of the continuum LES model. This learning module will be freely disseminated on the PI's research site. The DNS data and macroscale models on turbulence over porous beds will also be valuable for a wide range of fields, such as, noise control in aircraft trailing edges, heat and mass transfer in chemical and nuclear reactors, arterial blood flow and transport in endothelial walls, vegetation canopies; among others.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.

瞬时储存是河流生态学中最重要的概念之一，在预测淡水来源、营养物质循环和维持多样化的水生生态系统方面具有巨大的社会价值。缺乏一个准确的建模方法，占复杂的流动物理的湍流在渗透性床和耦合传输通过沉积物-水界面是一个关键的挑战，在实际规模的模拟自然水系统。典型的颗粒-地球仪溶质运移预测模型本质上是连续的，忽略了可渗透床上湍流水流与床内地下水流之间的直接耦合。 据推测，在沉积物-水界面的湍流可以显着改变砾石床内的瞬态存储和溶质保留时间。具体地说，多孔床上的湍流结构和动力学与不可渗透的粗糙壁上的湍流结构和动力学非常不同。量化的上升流和下降流事件在流床界面和它们的调制自由流湍流，以及渗透深度的湍流结构内的多孔床是至关重要的发展宏观尺度，连续介质为基础的建模溶质运移。这项跨学科的研究将培养两名博士生直接和大涡模拟，体积平均技术和多尺度分析。基本的数值实验，提出了湍流边界层的可渗透的砾石床代表溪流或河流。将使用基于PI开发的虚拟域方法的求解器，对自然溪流或河流中的代表性水流进行静态多孔床湍流的孔隙解析直接数值模拟（DNS）。湍流物理的范围内的渗透性雷诺数的单分散和多分散，随机填充砾石床将进行调查和对比粗糙，不透水的墙壁与类似的拓扑结构。详细的，时空的压力和速度波动数据的接口将被用来开发和验证大尺度，连续模型与可变孔隙度的大涡模拟（LES）。拟议的研究有可能改变目前国家的最先进的河段规模的溶质运移在河流管理中使用的建模方法。孔隙解析DNS数据将用于设计一个学习模块，用于研究生课程“湍流建模”，并对连续LES模型进行先验和后验分析。该学习模块将在PI的研究网站上免费传播。关于多孔床湍流的DNS数据和大尺度模型对许多领域也有价值，例如飞机后缘的噪声控制、化学和核反应堆中的热量和质量传递、动脉血流和内皮壁中的输送、植被冠层;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进行评估，被认为值得支持和更广泛的影响审查标准。

项目成果

Clustering of inertial particles in turbulent flow through a porous unit cell

通过多孔晶胞的湍流中惯性粒子的聚集

• DOI: 10.1017/jfm.2022.100
• 发表时间: 2022
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Apte, Sourabh V.;Oujia, Thibault;Matsuda, Keigo;Kadoch, Benjamin;He, Xiaoliang;Schneider, Kai
• 通讯作者: Schneider, Kai

Pore-resolved investigation of turbulent open channel flow over a randomly packed permeable sediment bed

• DOI: 10.1017/jfm.2023.636
• 发表时间: 2023-08
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: S. Karra;S. Apte;Xiaoliang He;Timothy Scheibe

Particle Resolved DNS Study of Turbulence Effects on Hyporheic Mixing in Randomly Packed Sediment Beds

随机填充沉积床中湍流对潜流混合影响的粒子解析 DNS 研究

• 发表时间: 2022
• 作者: Karra, S.;Apte, SV;and Scheibe, T.
• 通讯作者: and Scheibe, T.