调水工程输水渠道堰闸流量计算方法探讨

摘要

调水工程输水渠道堰闸流量计算方法的准确性是运行调度数字化、信息化的关键水力条件.传统的堰闸流量计算方法是先进行孔流、堰流判别,再根据相应的经验公式进行计算,其孔、堰流判断条件为闸门的相对开度e/H.经试验研究及理论分析论证认为:传统计算公式中以e/H=0.65作为宽顶堰孔流与堰流的判断条件,仅适用于自由出流状态.调水工程输水渠道堰闸工程正常运行条件一般为大淹没孔流,传统方法计算流量误差较大.通过系列模型试验数据的拟合,提出了特定条件下调水工程堰闸流量计算方法.%The calculation accuracy of flow at the weir sluice of water diversion project is a prerequisite for its digital operation.Traditional method of calculating discharge flow in hydraulics textbooks in general is to discriminate the flow pattern first,and then to calculate the discharge flow according to corresponding empirical formulas.The discrimination of flow pattern is determined by the relative opening e/H of gate.In the present research,by experimental and theoretical analysis,it is concluded that e/H =0.65 in the traditional formula as an index of discriminating orifice flow and weir flow is suitable only for free flow condition.It would cause big error in the calculation for long-distance water transfer projects,because it is not suitable for big submerged weir flow converting to submerged orifice flow.According to model test data,the fitted formula of calculating the discharge at weir sluice under specific conditions of water transfer project are presented.