权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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

基本信息

批准号：
125500987
负责人：
Professor Dr.-Ing. Jochen Fröhlich
金额：
--
依托单位：
Institut für Strömungsmechanik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/125500987?language=en
关键词：
resolution numerical experimental studies turbulence

项目摘要

(Abstract of the original proposal, still valid)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 by a combination of state-of-the-art physical experiments and numerical simulations. Key topics are 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 numbers, flow submergence, 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.

（原提案摘要，仍然有效）由水流引起的泥沙侵蚀和近床输运分析对水利工程的许多方面都至关重要，包括稳定河道的设计、桥墩的保护以及水生生境的开发和管理等。目前大多数用于预测泥沙侵蚀阈值和推移质输沙率的关系式都是经验性的，并采用时间和空间平均的整体数量。因此，这些公式的预测能力很低，误差可能远远超过100%，这反映了对所涉及的物理机制缺乏正确的理解。拟议的研究将通过结合最先进的物理实验和数值模拟来解决这一知识差距。主要议题是确定和量化瞬时流场（包括粗糙度顶部以下区域）与沉积物颗粒所受作用力之间的关系，评估单个推移质颗粒轨迹以及湍流与众多移动的沉积物颗粒之间的相互作用。除其他外，雷诺数，流动淹没，和沉积物包装湍流结构和近床运输的影响将得到解决。这项研究将首次系统地使用高分辨率数值模拟，充分分辨移动的粗糙度元素，并在移动的沉积床上下进行先进的三维实验测量。该项目将汇集来自两个国家的三个研究小组，它们在实现共同研究目标方面具有独特的能力。