High resolution numerical and experimental studies of turbulence-induced sediment erosion and near-bed transport

湍流引起的沉积物侵蚀和近床输送的高分辨率数值和实验研究

• 批准号: EP/G056404/1
• 负责人: Vladimir Nikora
• 金额: $ 55.52万
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG056404%2F1
• 关键词: resolution; numerical; experimental; studies; turbulence

Analysis of turbulence-induced sediment erosion and near-bed transport is vital to many aspects of hydraulic engineering including the design of stable channels, protection of bridge piers, and the development and management of aquatic habitats, to mention a few. Most currently available relationships for predicting sediment erosion thresholds and bed-load transport rates are empirical and employ time- and space-averaged bulk quantities. The predictive power of these formulae is therefore low and errors may well exceed 100 %, which is a reflection of the lack of sound understanding of the physical mechanisms involved. The proposed study will address this knowledge gap using state-of-the-art physical experiments and numerical simulations of flows over spherical and naturally shaped roughness elements. Key research targets include identification and quantification of relationships between instantaneous flow fields (including the region below roughness tops) and resulting forces on sediment particles, assessment of individual bed-load particle trajectories and the interaction of turbulent flow and a multitude of mobile sediment particles. Among others, the effect of Reynolds number, flow submergence, sediment shape, and sediment packing on turbulence structure and near-bed transport will be addressed. The study will be based, for the first time, on the systematic use of highly-resolved numerical simulations with fully resolved mobile roughness elements coupled with advanced three-dimensional experimental measurements above and below mobile sediment beds. The project will bring together three research groups from two countries which complement each other with unique capabilities in addressing a common research goal.

湍流引起的泥沙侵蚀和近河床输送的分析对于水利工程的许多方面都至关重要，包括稳定渠道的设计、桥墩的保护以及水生栖息地的开发和管理等等。目前大多数用于预测沉积物侵蚀阈值和底质输送速率的可用关系都是经验关系，并且采用时间和空间平均散装量。因此，这些公式的预测能力很低，错误可能远远超过 100%，这反映出对所涉及的物理机制缺乏充分的理解。拟议的研究将利用最先进的物理实验和球形和自然形状粗糙度元素上的流动数值模拟来解决这一知识差距。主要研究目标包括识别和量化瞬时流场（包括粗糙度顶部下方的区域）与沉积物颗粒上产生的力之间的关系，评估单个床载颗粒轨迹以及湍流和大量移动沉积物颗粒的相互作用。其中，雷诺数、水流淹没、沉积物形状和沉积物堆积对湍流结构和近床输送的影响将得到解决。该研究将首次基于系统地使用高分辨率数值模拟、完全解析的移动粗糙度元素以及移动沉积层上方和下方的先进三维实验测量。该项目将汇集来自两个国家的三个研究小组，这些研究小组在实现共同研究目标方面具有独特的能力，相互补充。

项目成果

A novel experimental technique and its application to study the effects of particle density and flow submergence on bed particle saltation

• DOI: 10.1080/00221686.2016.1233583
• 发表时间: 2017-01-01
• 期刊: JOURNAL OF HYDRAULIC RESEARCH
• 影响因子: 2.3
• 作者: Amir, Mohammad;Nikora, Vladimir;Witz, Matthew
• 通讯作者: Witz, Matthew

3D Lagrangian modelling of saltating particles diffusion in turbulent water flow

• DOI: 10.2478/s11600-012-0003-2
• 发表时间: 2012-12-01
• 期刊: ACTA GEOPHYSICA
• 影响因子: 2.3
• 作者: Bialik, Robert J.;Nikora, Vladimir I.;Rowinski, Pawel M.
• 通讯作者: Rowinski, Pawel M.

Drag forces on a bed particle in open-channel flow: effects of pressure spatial fluctuations and very-large-scale motions

• DOI: 10.1017/jfm.2018.1003
• 发表时间: 2019-01
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: S. Cameron;V. Nikora;Ivan Marusic

Entrainment of sediment particles by very large-scale motions

• DOI: 10.1017/jfm.2020.24
• 发表时间: 2020-02
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: S. Cameron;V. Nikora;M. Witz

Pressure forces on sediment particles in turbulent open-channel flow: a laboratory study

• DOI: 10.1017/jfm.2014.498
• 发表时间: 2014-09
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: M. Amir;V. Nikora;M. Stewart