连续丁坝回流特性实验研究

发布时间：2018-03-31 15:04

本文选题：河流动力学　切入点：丁坝　出处：《水力发电学报》2017年10期

【摘要】：丁坝是水利工程中最为常见的水工建筑之一,丁坝区产生的回流将引起复杂的河道流速分布和泥沙输移过程,对于船舶航行和水利工程有着重要的影响。现有丁坝水沙特性研究多集中于数学模型方面,现场实测资料和模型实验等直接观察得到的数据非常有限。本文通过室内大型水槽进行的实体模型实验,模拟水流在连续丁坝区的回流形态。通过粒子跟踪测速技术对全流场的水流流速、分布进行了测量,记录流量和水深过程,并对水流回流特性进行了分析。实验结果表明:(1)采用电磁流量计量测结果准确,水深变化过程稳定;(2)丁坝区的回流存在纵向零流速线,将其沿横向划分为主流区、回流正区和回流负区,沿纵向划分为增流区和减流区,横向障碍物前存在次生回流;(3)回流流量呈现中心稳定两侧迅速增减,最大可达上游来流量的50%。实验成果可为更加深入地研究丁坝区回流和泥沙冲淤特性提供可靠的数据,为数值模拟提供详细的验证资料,进而对航道设计及河岸维护等工程实际提供科学的支撑作用。
[Abstract]:Spur dike is one of the most common hydraulic structures in water conservancy projects. The reflux produced in Ding dam area will cause complex river flow velocity distribution and sediment transport process. It has an important influence on ship navigation and water conservancy engineering. The existing researches on the characteristics of groin water and sediment are mainly focused on mathematical models. The data obtained by direct observation, such as field measured data and model experiments, are very limited. The flow velocity and distribution in the whole flow field were measured by particle tracking and velocimetry, and the flow rate and water depth were recorded. The experimental results show that the measurement results by using the electromagnetic Flowmeter are accurate and the water depth variation process is stable. There is a longitudinal zero velocity line in the return flow in the dam area, which is divided into the mainstream area along the transverse direction. The positive and negative circumfluence regions are divided into increasing and decreasing areas along the longitudinal direction, and the secondary reflux in front of the transverse obstacles increases and decreases rapidly on both sides of the central stability. The experimental results can provide reliable data for more in-depth study on the characteristics of backflow and sediment scouring and deposition in the Dingdam area, and provide detailed verification data for numerical simulation. Furthermore, it can provide scientific support for waterway design and river bank maintenance.
【作者单位】：清华大学水沙科学与水利水电工程国家重点实验室;
【基金】：水沙科学与水利水电工程国家重点实验室科研课题项目(2015-KY-2)
【分类号】：TV863

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