U形渠道竖向流速分布规律及测流技术研究

在分析国内外学者对明渠水流流速分布规律研究成果的基础上,利用二次函数和对数公式对U形渠道实测流速值进行拟合,发现二次函数形式拟合曲线的相关性在0.93左右,对数形式拟合曲线的相关性在0.75左右。引入尾流函数修正后的对数公式,拟合曲线的相关性达到0.96左右。尾流函数修正后的对数公式中的尾流强度系数取不同值时,流速拟合曲线交于一点。对交点分析得出,在不同的水力特性下,交点水深与测线水深的比值范围固定在0.1~0.2之间,交点流速值与断面平均流速值有很好的对应关系。

Velocity Distribution of Vertical and Measurement Technology in Open Channel with U-shaped Cross-section

Based on the study on velocity distribution of open channel by scholars from our country and abroad,this paper makes the experimentation into channel with U-shape cross-section.We used parabola function and log law to simulate the practical velocity data from vertical of water across section,we found the relativity respective reached about 0.93 and 0.75.We introduced the revised log law by wake-stream function,the relativity respective reached 0.96.Choosing different wake steam intensive parameter,we get the simulative curve of practical velocity intersect one point.The ratio range between depth of the point and depth of channel is fix up 0.1～0.2,and the velocity of point and average velocity of channel have nice relativity.