Analytical and experimental study of velocity distribution in adverse-slope channel flow

Abstract

The prediction of the velocity distribution in adverse-slope flow is improved by analytical and experimental study of the wake and dip effects, based on the log-wake-dip velocity law. This improved equation allows accurate prediction of the wake phenomenon and dip phenomenon. The equation compares very well with the experimental data obtained in the present study and some reference data, and it predicts better than other formulations available in the literature. This study shows that the wake-parameter can be expressed by the linear equation for the pressure-gradient parameter, under the conditions of the respective Reynolds number and aspect ratio. The dip-parameter can be determined as constants using the known position of the maximum velocity point. When the pressure gradient is relatively small, the wake effect is a boost to velocity. In contrast, when the pressure gradient is relatively large, the wake effect is an impediment to velocity.