An Analytical Model for Velocity Distribution and Dip-Phenomenon in Uniform Open Channel Flows

Abstract

An analytical equation for velocity distribution in uniform open-channel flows is proposed based on an eddy viscosity with a modified wake correction and on an analysis of shear stress distribution. The proposed equation for the velocity distribution in vertical direction is able to predict the velocity-dip-phenomenon. The new log-wake modified eddy viscosity model is compared with the previous models. The proposed equation i. e., total-dip-modified-log-wake law for velocity distribution is compared with the experimental data obtained by Coleman, Wang and Qian, Lyn and Kironoto and Graf. The total-dip-modified-log-wake law agrees well with the experimental data and predicts the velocity dip position accurately. It has been found that the Coles' wake strength has significant effect on the location of the dip position and the value increases with the increase of dip-correction parameter.