近底水流结构与推移质输移规律试验研究
发布时间：2019-05-25 02:53
【摘要】：近底泥沙运动与床面附近的水流结构密切相关,精细研究不同水流与边界条件下近底水流结构空间、时间上的差异,对于揭示近底泥沙运动输移复杂多变性规律具有更为直接有效的学术意义。本文通过开展系列水槽试验,利用ADV测速及高速摄像技术,精细采集了近壁区的流速及紊动特征值,分条带计量了推移质输移情况。通过对比横向密布测点的流速结构差异,剖析了近底流速时空分布的不同变化特点与两侧的流速结构变异。基于输沙分条带量化观测模式,得以对推移质输移的空间横向分布特性进行了细致的分析。此外通过流速测点与输沙条带时间、空间上的同步关联分析,探讨了探索两者之间的关系,认为水流的流速分布与其紊动结构影响推移质输移,其中脉动强度的作用十分明显。在本次水槽试验中,重点研究近底区域水沙运动特性及推移质输移的横向分布规律。采用精密可变坡水槽设备进行相关试验,由ADV进行实验断面的流速测量;推移质泥沙输移的动态输移记录由动态量测装置实时记录。从动态的输沙过程采集和瞬时流速去分析近底水流结构对推移质输移的影响。分析不同水流条件下的实验结果发现,横向输沙量从中间条带向两边条带逐渐减少,大体呈现偏态分布;分析发现在水流的近底区域,其横向流速的流速分布和紊动强度对于输沙的横向分布会有较大的影响,并且明渠恒定流推移质输沙率和断面流速的横向分布是造成床面形态的原因。推移质输沙的横向分布是泥沙运动力学中有待深入研究的关键问题之一,关于推移质泥沙的输移机理、影响因素、计算方法的研究还需要进一步的探索。
[Abstract]:The near bottom sediment movement is closely related to the flow structure near the bed surface. The spatial and temporal differences of the near bottom flow structure under different flow and boundary conditions are studied in detail. It is of more direct and effective academic significance to reveal the complex variability of sediment movement and transport near the bottom. In this paper, a series of flume tests are carried out, ADV velocimeter and high-speed camera technology are used to collect the velocity and turbulent eigenvalues near the wall, and the bed load transport is measured in strips. By comparing the velocity structure difference of the transverse dense measuring point, the different variation characteristics of the temporal and spatial distribution of the velocity near the bottom and the variation of the velocity structure on both sides are analyzed. Based on the quantitative observation model of sediment transport strip, the spatial transverse distribution characteristics of push load transport are analyzed in detail. In addition, through the synchronous correlation analysis between the velocity measurement point and the time and space of the sediment transport strip, the relationship between the two is discussed. It is considered that the velocity distribution of the flow and its turbulent structure affect the transfer of the transfer material, in which the pulsating intensity plays a very obvious role. In this flume experiment, the movement characteristics of water and sediment near the bottom and the transverse distribution of push load transport are studied. The related tests are carried out by precision variable slope flume equipment, and the velocity measurement of the experimental section is carried out by ADV, and the dynamic transport record of bed load sediment transport is recorded in real time by the dynamic measuring device. The influence of near-bottom flow structure on push load transport is analyzed from dynamic sediment transport process collection and instantaneous velocity. The experimental results under different flow conditions show that the lateral sediment transport decreases gradually from the middle band to the two sides of the band, and shows a skewness distribution. It is found that the velocity distribution and turbulence intensity of the transverse velocity have a great influence on the transverse distribution of sediment transport near the bottom of the flow. The bed shape is caused by the constant flow load transport rate and the transverse distribution of cross section velocity in open channel. The transverse distribution of bed load sediment transport is one of the key problems to be further studied in sediment transport dynamics. The research on the transport mechanism, influencing factors and calculation methods of bed load sediment transport needs to be further explored.
【学位授予单位】：华北水利水电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV142.2
本文编号：2485429
[Abstract]:The near bottom sediment movement is closely related to the flow structure near the bed surface. The spatial and temporal differences of the near bottom flow structure under different flow and boundary conditions are studied in detail. It is of more direct and effective academic significance to reveal the complex variability of sediment movement and transport near the bottom. In this paper, a series of flume tests are carried out, ADV velocimeter and high-speed camera technology are used to collect the velocity and turbulent eigenvalues near the wall, and the bed load transport is measured in strips. By comparing the velocity structure difference of the transverse dense measuring point, the different variation characteristics of the temporal and spatial distribution of the velocity near the bottom and the variation of the velocity structure on both sides are analyzed. Based on the quantitative observation model of sediment transport strip, the spatial transverse distribution characteristics of push load transport are analyzed in detail. In addition, through the synchronous correlation analysis between the velocity measurement point and the time and space of the sediment transport strip, the relationship between the two is discussed. It is considered that the velocity distribution of the flow and its turbulent structure affect the transfer of the transfer material, in which the pulsating intensity plays a very obvious role. In this flume experiment, the movement characteristics of water and sediment near the bottom and the transverse distribution of push load transport are studied. The related tests are carried out by precision variable slope flume equipment, and the velocity measurement of the experimental section is carried out by ADV, and the dynamic transport record of bed load sediment transport is recorded in real time by the dynamic measuring device. The influence of near-bottom flow structure on push load transport is analyzed from dynamic sediment transport process collection and instantaneous velocity. The experimental results under different flow conditions show that the lateral sediment transport decreases gradually from the middle band to the two sides of the band, and shows a skewness distribution. It is found that the velocity distribution and turbulence intensity of the transverse velocity have a great influence on the transverse distribution of sediment transport near the bottom of the flow. The bed shape is caused by the constant flow load transport rate and the transverse distribution of cross section velocity in open channel. The transverse distribution of bed load sediment transport is one of the key problems to be further studied in sediment transport dynamics. The research on the transport mechanism, influencing factors and calculation methods of bed load sediment transport needs to be further explored.
【学位授予单位】：华北水利水电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV142.2
【参考文献】
相关期刊论文 前10条
1 孙东坡;刘明潇;王鹏涛;李国栋;赵亚飞;董明家;;双峰型非均匀沙推移运动特性及输移规律[J];水科学进展;2015年05期
2 刘明潇;孙东坡;王鹏涛;赵亚飞;韩力球;;双峰型非均匀沙粗细颗粒相互作用对推移质输移的影响[J];水利学报;2015年07期
3 王浩;李丹勋;陈启刚;王兴奎;;基于图像处理的明渠紊流近壁区条带结构试验[J];水科学进展;2015年02期
4 唐立模;孙会东;刘全帅;;明渠紊流与床面形态相互作用研究进展[J];水利水电科技进展;2015年02期
5 陈有华;白玉川;;平衡输沙条件下非均匀推移质运动特性[J];应用基础与工程科学学报;2013年04期
6 刘明潇;张晓华;田世民;孙东坡;;推移质泥沙输移研究回顾与展望[J];水运工程;2013年05期
7 杨克君;聂锐华;曹叔尤;刘兴年;;清水作用下全动床复式河槽泥沙输移特性及其模拟[J];四川大学学报(工程科学版);2013年02期
8 聂锐华;杨克君;刘兴年;曹叔尤;;非均匀沙卵石推移质输移随机分布研究[J];水利学报;2012年S2期
9 卢金友;詹义正;赵根生;魏丽;;河道中受侧壁影响的断面流速分布规律研究[J];水利学报;2012年06期
10 聂锐华;黄尔;刘兴年;曹叔尤;;非均匀沙卵石推移质输移随机特性研究[J];水利学报;2012年04期
相关博士学位论文 前2条
1 马宏博;推移质运动的随机力学理论[D];清华大学;2014年
2 陈有华;非均匀推移质泥沙运动特性研究[D];天津大学;2013年
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