Author(s): Xingkui Wang; Zhao-Yin Wang; Mingzhong Yu; Danxun Li
Abstract: The log-law and wake-law of velocity profile of open channel flow of sediment suspensions are discussed and compared in the paper. Data from 9 literatures are employed for comparison of the two laws and regression analyses are conducted on the main factors affecting velocity profile. Empirical formulas are obtained for estimation of the factors from the flow conditions. The elevation of the maximum velocity and the deviation of velocity from the logarithmic formula at the water surface are functions of the aspect ratio of the channel. The log-law is developed into Eq. (20) applicable to the whole flow including the region near the water surface for various boundary conditions. The wake law describes the velocity distribution below the maximum velocity point. The relative error of wake-law (11%) is larger than that of log-law (6%). Moreover, the wake coefficient must be determined by using the measured velocity profile because there is no reliable formula to estimate its value from the flow conditions.