Prediction of Flow-Regime Transition over a Stepped Channel

Abstract

For the hydraulic design of a stepped channel, it is crucial to estimate the limit of flow regimes. Step flow in the quasi-uniform region of a stepped channel is analyzed theoretically in this paper. The present work adopts a flow-regime criterion and some assumptions from a method from the literature, a specific energy equation is established, and a weak assumption from the literature is modified to determine the flow conditions in and out of the control volume (CV). A pragmatic method is therefore provided to predict the onset of skimming flow in the quasi-uniform region, and its accuracy is examined through comparison with data from two experimental tests and previous studies.