矩形明渠层流垂向流速分布类型研究

Study on Vertical Velocity Distribution of Rectangular Open Channel

为找寻准确合理的明渠水流垂向流速分布类型,采用理论分析方法对明渠流动的理论解进行解读,按抛物型分布、指数型分布、对数型分布3种形式绘制垂向流速分布图进行比较,发现不能采用统一的对数型流速分布来表示全断面流速分布。二维明渠理论解的垂向流速分布验证表明,无量纲的垂向流速分布只能是无限逼近理论最大值,与实际情况有出入,真实的流速分布规律应由理论流速分布与实际流速分布二者去逼近。

In order to find an accurate and reasonable expression of velocity distribution,the theoretical solution of open channel flow was interpreted by means of theoretical analysis,and vertical velocity distribution diagrams were drawn to compare according to parabolic distribution,exponential distribution and logarithmic distribution.The results show that the uniform logarithmic velocity distribution cannot be used to represent the velocity distribution of the whole section.The verification of the vertical velocity distribution of the theoretical solution of two-dimensional open channel shows that the dimensionless vertical velocity distribution can only approach the theoretical maximum,which is different from the actual situation.The real velocity distribution should be approximated by theoretical velocity distribution and actual velocity distribution.