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，其特征是化学物质和污染物、有机物、溶解氧、营养物质和热量等溶质在河流-砾石界面上的滞留和运输，在预测淡水饮用水来源、养分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。缺乏一种精确的模拟方法来解释渗透床上复杂的湍流物理和泥沙-水界面上的耦合输运，是自然水体系实际尺度模拟的关键挑战之一。典型的颗粒到颗粒的溶质运移预测模型本质上是连续的，忽略了透水床上的湍流流动和床内地下水流动之间的直接耦合。假设沉积物-水界面处的湍流可以显著改变砾石床内的瞬时存储和溶质保留时间。具体地说，多孔床面上的湍流结构和动力学可能与不透水的粗糙壁面上的完全不同。定量确定床面上涌和下涌事件及其受自由流湍流的调制，以及湍流结构在多孔床内的穿透深度，对于发展基于连续介质的宏观溶质运移模拟是至关重要的。这项跨学科研究将对两名博士生进行直接和大涡模拟、体积平均技术和多尺度分析的培训。提出了代表河流或河流流动的可渗透砾石床上的湍流边界层的基本数值实验。对于天然溪流或河流中的典型水流，将使用PI开发的基于虚拟区域方法的求解器，对固定的多孔河床上的湍流进行孔隙分辨的直接数值模拟(DNS)。在一定的渗透雷诺数范围内，研究了单分散和多分散随机堆积砾石床的湍流物理，并与具有相似拓扑结构的粗糙不透水壁面上的湍流物理进行了对比。界面上详细的时空压力和速度起伏数据将被用来开发和验证用于大涡模拟(LES)的具有可变孔隙率的大尺度连续介质模式。这项拟议的研究有可能改变目前河流管理中使用的最先进的REACH尺度溶质运移建模方法。通过对连续统大涡模型的先验分析和后验分析，将利用孔隙解析的域名系统数据，为研究生水平的“湍流建模”课程设计一个学习模块。这一学习单元将在国际和平研究所的研究网站上免费传播。关于多孔床上湍流的DNS数据和宏观尺度模型也将在广泛的领域中发挥重要作用，例如飞机尾缘的噪声控制、化学反应和核反应堆中的热量和质量传递、内皮壁中的动脉血流和传输、植被树冠等。该奖项反映了NSF的法定使命，并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，被认为值得支持。

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.