A SIMPLE MODEL OF A VELOCITY DISTRIBUTION IN ACCELERATING/DECELERATING FLOWS AND ITS APPLICATION TO DEPTH-AVERAGED FLOW MODEL

Abstract

In open channel flows with variations of bed topography, the flow is influenced by accelerating/decelerating effects. A simple model of a velocity distribution in such flows was proposed in this paper. In the model building, we assume that a fundamental form of velocity distribution is expressed as a power law and substitute it into a steady equation of motion. Then, the coefficients of the power law are theoretically derived by making the terms at each orders zero. The characteristics of this model are examined through the comparison with the experiments by Song&Graf. In addition, the bed shear stress in this model is examined to apply it to the depth-averaged flow model.