EXPERIMENTAL INVESTIGATION ON ARTIFICIAL CONTROL AGAINST PERIODICALLY DEFLECTED FLOW IN SUBMERGED HYDRAULIC JUMP

Abstract

 If a submerged hydraulic jump has a large submergence, a high velocity flow below a sluice gate is located near the bottom. When the main flow lifts to the water surface from the channel bottom, at a certain stage, the main flow is periodically deflected. In this case, it might be difficult for swimming fishes to migrate upstream through the hydraulic structure, even if the fish passage is installed at the downstream of the structure.

 In this study, the installation of baffle blocks with diagonal upstream face at the downstream of a sluice gate was proposed in order to disappear a periodically deflected flow in submerged hydraulic jump. The experiments yield that the periodically deflected flow can be disappeared by optimal installation of baffle blocks. The artificially controlled flow has been characterized by time averaged velocity and the velocity with time series.