摘要
通过水槽实验研究,分析了河流的水流流速分布受堆积体影响的特性,其结果表明:(1)受堆积体影响,水流流态一般可分为4个区段,即水流的主流区、堆积体上游滞流区、堆积体下游回流区及堆积体下游主流区和回流区之间的过渡区。(2)堆积体体型对主流流速沿程变化影响很大,一般阻水率越大,其对主流流速影响幅度越大,影响范围也越大。堆积体上游段,主流流速受堆积体影响流速减小;堆积体段,主流流速显著加大,堆积体末端附近,流速达到最大;堆积体下游段,水流逐渐扩散,主流流速逐渐减小,但主流流速仍较无堆积体情况明显加大。(3)水流主流流速变化与流量之间无确定相关关系,堆积体对主流流速沿程影响特性完全与堆积体阻水率的变化特性相一致。(4)引入堆积体阻水率概念,堆积体的阻水率对水流结构的影响起决定性作用,阻水率越大,其对水流结构影响越大。
Based on the flume experimental study, the characteristics of the distribution of channel flow velocity under the impact from deposit are analyzed herein. The result shows that 1. Under the impact from deposit, the flow pattern can be divided into four sections, i.e. the main flow zone, the stagnation flow zone upstream of deposit, the baekflow zone downstream of deposit and the transition zone downstream of deposit between both the main flow zone and the backflow zone. 2. The impact from the shape of deposit is significant on the variation of the velocity of the main flow along river channel. 3. No definite correlative relation is there between the variation of main flow velocity and the flow rate, while the characteristics of the impact from deposit on the variation of main flow along river channel is fully coincided with the changing characteristics of the water resistance ratio of deposit. 4. The water resistance ratio has a predominant effect on the impact from deposit on the flow structure concerned; i.e. the larger the water resistance ratio is, the greater the impact from it upon the flow structure will be.
出处
《水利水电技术》
CSCD
北大核心
2011年第11期38-41,共4页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(50949057)
973计划资助(2011CB409903)
关键词
堆积体
水流结构
阻水率
水槽实验
deposit
flow structure
water resistance ratio
flume experiment
