宽浅陡槽水流的稳定性及控导措施  

Stability of shallow flow in wide-steep channel and its adjusting work

作　　者：孙东坡[1] 薛海[1] 宋永军[1] 王二平[1] 刘晓平[1] 

机构地区：[1]华北水利水电学院,河南郑州450011

出　　处：《武汉大学学报（工学版）》2008年第3期29-33,42,共6页Engineering Journal of Wuhan University

基　　金：国家自然科学基金资助项目(编号:50779019)

摘　　要：对宽浅陡槽水流特性、下游衔接消能及控导措施进行了试验与理论研究,分析表明浅层急流能量损耗比一般明流大,陡槽水流有2种不同特点的动量横向分布规律:一般陡槽(宽深比B/h<40,单宽流量q>3.4m3/s.m)末端水流呈"马鞍型"动量横向分布,水流具有较强的稳定性;而大宽深比(B/h>40,单宽流量q<3.4m3/s.m)陡槽末端水流呈"椭圆型"动量横向分布,这种分布态势缺乏对外界干扰的遏制能力.宽浅陡槽水流不稳定是动量横向分布缺乏强大的两翼控制,使微小干扰形成累加递增的类"多米诺骨牌效应",导致末端水跃的不稳与消能不充分.基于"介入式"原理,利用急流干扰波传播与反射特点,采用潜没式三角翼体调整动量分布、改善下游衔接水流稳定性,取得了良好的效果.对三角翼体的控导机理及主要影响因素进行探讨,提出了三角翼体型参数的优化确定方法,可供实际工程参考.The properties of shallow supercritical flow in the steep channel and influence of joint at downstream have been studied. First, the character of energy dissipation is analyzed; and it is concluded that the resistance loss of this flow is more than that of the general open flow. Then the flow momentum distribution in wide steep channel is analyzed; and it is found that when the ratio B/h〈40 and the discharge is larger, the flow momentum lateral distribution in the end of steep channel presents a saddle profile which has stronger stability; but when the ratio B/h〉40 and the discharge is smaller, the momentum lateral distribution presents a elliptical profile which has bad stability and can＇t restrain the boundary disturbance. Based on analyzing, it is found that the instability of shallow flow in the end of steep chan nel originates from lack of both stronger wings control in momentum lateral distribution, and brings about accumulation and increase of minor disturbance, named “Domino effect”. At last, it leads to instability of end hydraulic jump and insufficiency of energy dissipation. In order to improve stability of join flow at downstream, a measure adjusting of momentum lateral distribution has been put forward. Based on intervene principle, a new adjusting work has been taken by submerged triangle wing and has got satisfied effect. The control mechanism, main factors and some design method of submerged triangle wing for engineering are discussed.

关 键 词：潜没式三角翼 水力模拟 “马鞍型”动量分布 骨牌效应 

分 类 号：TV653[水利工程—水利水电工程]