The impact characteristics analysis of free over-fall flow on downstream channel bed

Abstract

This article has investigated the impact characteristics of free over-fall flow. The theoretical equations of impact force and impact position on the downstream channel with bed slope have been derived for the first time in this study. Dimensionless analysis was used to obtain the influence factors of impact force and impact position. A series of laboratory experiments, which adopted bed slopes in the range of 0–9%, and Drop numbers of to , were carried out to establish the regression equations of impact force and impact position using the influence factors. Experimental outcomes confirm the usefulness of the theoretical equations. If the flow state of free over-fall flow is located within the experimental condition, we can calculate the impact force and impact position of free over-fall flow using the equations developed in this study. Moreover, the maximum impact pressure head, the impact position and the impact force increase with an increase in bed slope and the Drop number of the downstream channel.