明渠收缩段水深变化规律模型试验

An Experimental Investigation of the Water Depth Change Laws on the Contraction Sections of Open Channels

通过水力学模型试验,对收缩段内水深变化规律进行观测,分析了收缩角、底坡及流量的变化对收缩段内流态影响,总结出三者对水深变化及水面波动的影响规律,得到了收缩段出口Fr随收缩角和流量的变化关系。根据动量定理推导了收缩段内壅水水深的计算公式,公式计算得到的收缩段内水深与试验测得水深基本一致。

The hydraulic model tests were carried out to study the water depth change rules in the contraction section.The influences of the convergence angles in planning,the bottom slope and the flow rate on the flow patterns were analyzed.The water depth change laws and the water surface fluctuation were carried out.The relationships of the Froude numbers at the end of contraction section and the convergence angle and the flow rates were obtained.Furthermore,a formula with the purpose of calculating the water depth increases in contraction section were also derived from Momentum Theorem,and the comparison between the calculated water depth and the experimental depth shows that the formula can be used to calculate the water depth increase in the open channel contraction sections.