高原环境下WES剖面实用堰流量系数分析

Analysis of Practical Weir Flow Coefficient of WES Section Practical Weir in Altitude Environment

本文依托西藏农牧学院-多功能变坡水槽,以WES剖面型实用堰为模型开展堰流流量系数测定实验,改变流量测得相应的堰顶水头H和断面流速v0,计算出堰顶全水头H0和相应流量系数m值,并对海拔3000 m地区WES剖面型实用堰流量系数经验公式进行拟合。结果表明:当上游堰高P1/设计水头Hd=1时,在海拔3000 m时WES剖面型实用堰流量系数m随堰顶全水头H_(0)与设计水头Hd比值的增大而增大,与海拔30 m相比,二者变化趋势大致相同,但是同一比值情况下,海拔在3000 m时流量系数要大于海拔30 m时的流量系数,最大差值可达4.60%;海拔3000 m地区WES剖面型实用堰流量系数经验公式为m=0.03963(H_(0)/H_(d))^(3)-0.17984(H_(0)/H_(d))^(2)+0.29027(H_(0)/H_(d))+0.34957,经验公式计算流量与实测流量之间最大绝对百分误差为3.32%。

In this paper,relying on multi-functional variable slope sink and trough in Tibet Agriculture and Animal Husbandry University,the weir flow coefficient measurement experiment was carried out using the WES profiled practical weir as the model to measure the corresponding weir top head and section flow velocity by changing the flow rate,and H0 and corresponding m values were calculated.The empirical formula of WES profile practical weir flow coefficient at an altitude of 3000 m was fitted.The results showed that when the upstream weir height P1/design head Hd equaled 1,the flow coefficient m of WES profile type practical weir increased with the increase of the ratio of total head H0 to design head Hd at an altitude of 3000 m,and the change trend of the two was roughly the same compared with 30 m altitude,but under the same ratio,the flow coefficient at 3000 m altitude was greater than the flow coefficient at 30 m above sea level,and the maximum difference reached 4.60%.The empirical formula of WES profiled practical weir flow coefficient in the altitude of 3000 m was m=0.03963(H_(0)/H_(d))^(3)-0.17984(H_(0)/H_(d))^(2)+0.29027(H_(0)/H_(d))+0.34957,and the maximum absolute percentage error between the flow rate and the measured flow was 3.32%.