宽浅陡槽水流动量分布特性及影响分析  

Analysis of momentum distribution and influence of shallow flow in the wide-steep channel

作　　者：孙东坡[1] 严军[1] 罗秋实[2] 戴小琳[3] 

机构地区：[1]华北水利水电学院,河南郑州450011 [2]武汉大学,湖北武汉430072 [3]江苏省水利厅,江苏南京210029

出　　处：《水科学进展》2006年第5期685-692,共8页Advances in Water Science

基　　金：国家自然科学基金资助项目(E090401和50279009)~~

摘　　要：对宽浅陡槽水流特性及其对下游消能衔接影响进行了试验研究。首先通过对浅层急流边界层的发展、掺气特点的分析探讨,得到了宽浅陡槽水流阻力损失比一般陡槽急流大许多的能量损耗特点及相应流速系数的范围值。分析了不同水流、边界条件下宽浅陡槽水流动量分布的特性,发现宽深比<40而流量较大时,陡槽末端呈“马鞍型”动量横向分布,具有较强的稳定性与抗干扰性;宽深比>40而流量较小时,陡槽末端呈“椭圆型”动量横向分布,这种态势缺乏对外界干扰的遏制能力,稳定性很差。指出,宽浅陡槽末端水流不稳定源于浅层急流断面动量横向分布缺乏强大的两翼控制,形成微小干扰累加递增作用,最终导致末端水跃的不稳与消能不充分,并提出了调整动量分布改善下游衔接水流稳定性的措施。In this paper the flow properties and influence on the joint at downstream are studied. First, by analyzing on the development of boundary layer in the shallow supercritical flow and aeration properties, we find the character of energy dissipation that the resistance loss of shallow flow in the and get its range value of the velocity coefficient. wide-steep channel is more than that of the flow in the general steep channel, Then, according to the different flow and boundary condition, we analyze the flow momentum distribution in wide steep channel, and find that when the ratio B/H 〈 40 and the discharge is larger, the flow momentum lateral distribution in the end of steep channel shows a saddle profile which has stronger stability and anti-disturbance; but when the ratio B/H 〉 40 and the discharge is smaller, the momentum lateral distribution shows a elliptical profile which has bad stability and can＇t restrain the outside disturbance. Based on analyzing the we attains that the instability of shallow flow in the end of steep channel originates from lack of stronger both wings control in momentum lateral distribution, which brings about accumulation and increase progressively of minor disturbance and leads to instability of the end hydraulic jump and insufficiency of the energy dissipation. In order to improve stability of join flow at downstream, a measure adjusting of momentum lateral distribution is put forward in this paper.

关 键 词：宽浅陡槽 浅层急流 能量损耗 动量分配模比系数 斜坡水跃 

分 类 号：TV653[水利工程—水利水电工程]