U形渠道圆头量水柱的数值模拟

为进一步研究U形渠道圆头量水柱过流特性及测流精度,利用Flow-3D软件对U形渠道圆头量水柱水力特性进行数值模拟,将渠道水流流态及水面线的实测值与模拟值进行对比,同时研究不同规格的圆头量水柱流量与驻点水深的关系及水头损失情况,并拟合出其流量公式。结果表明:模拟值与实测值的相对误差10%,两者具有较好的一致性,数值模拟结果可为圆头量水柱的结构优化提供依据。流量与驻点水深有很好的线性相关关系,相关系数0.98;水头损失随收缩比的减小而增大,相比量水槽水头损失较小,但顺流长度过大,水头损失反而增大;根据数据拟合出的流量公式,最大相对误差为9.74%,平均误差为2.66%,满足精度要求。

Numerical simulation of water-measuring pillar with round head in the U-shaped channel

In order to study the flow characteristics and measuring accuracy of water-measuring pillar with round head in the U-shaped channel, the hydraulic characteristics was simulated based on Flow-3D software.The channel flow regime and the values of the water surface line that measured and simulated were compared for the study of the relationship between the water flow and the stagnation of the water depth,as well as the water head loss.The corresponding flow formula was derived.The results showed that the relative error between the measured and simulated values was <10%,and both of them had good consistency.The numerical results could provide basis for the structure optimization of the water-measuring pillar with round head.It was found the existence of good linear relationship between flow and stagnation of water depth,and the correlation coefficient could reach 0.98.The head loss increased with the decrease of the contraction ratio.The loss was smaller compared to the flumes,however,the head loss would get to increase if the flow length was too big.Based on the calculation of the fitting flow formula,the maximum relative error was 9.74%,and the average error was 2.66%,which could meet the accuracy requirements.