糙条应用于弯段溢洪道内水力特性试验研究

Hydraulic Characteristic Study about Roughness Strip in Applied to Curved Spillway

为研究溢洪道弯段泄槽内布置糙条后的水力特性,选取槽内无糙条方案与布置糙条方案,从水深均匀度、横断面弗劳德数、凹凸岸水位三方面分析糙条对弯道水流的影响。结果表明,在淹没糙条的流量条件下,糙条的置入不仅可改善溢洪道横断面水深分布不均问题,还可缩短下游直线段距离;一定工况下,糙条可将溢洪道流态由急流转变为缓流;糙条对水流的控导作用将弯道底部水流由凸岸强迫导向凹岸,不仅消减水面横比降,还可抑制水流冲击波。

In order to study the hydraulic characteristics of spillway with roughness in the curved section of spillway,this paper compared the roughness-free scheme and roughness scheme.The impact of roughness on water flow in bend was analyzed from three aspects of water depth uniformity,cross-sectional Froude number,concave and convex bank water level.The results show that under the flow condition of submerged roughness,the placement of roughness not only improves the uneven distribution of water depth in the cross section of spillway,but also can shorten the downstream straight line distance;Under certain working conditions,the rough strip can change the spillway flow pattern from supercritical flow to subcritical flow.Water flow at the bottom of the bend is forced to lead from the convex bank to the concave bank by the control effect of roughness on the water flow,which not only reduces the horizontal gradient of water surface,but also inhibits the water flow shock wave.