HYDRAULIC JUMPS AT ROUNDED DROP

Among the variety of efficient energy dissipators, the stilling basin with a bottom drop is of particular significance. Based on a suggestion by Sharp, the flow configuration involving a large standing wave may be inhibited when rounding the drop. In this Paper, the wave type flow together with other jump configurations are experimentally analysed. Expressions are derived for the tailwater depth, the length of surface roller, the length of jump, as well as for typical quantities related to each type of flow. The analysis of data is based on a new approach by considering the effects of the jump and the drop geometry separately. Further, the intermediate flow configurations between each flow type are described and illustrated with photographs. The upper limit of wave appearance can be shown to depend only on the relative drop height. Therefore, the results of Sharp and the recent findings of the Authors relative to the wave type flow at abrupt drops could be significantly extended.