Abstract
This paper introduces a new design concept for energy dissipation below flow regulators. Instead of using a single-leaf sluice gate, a double-leaf gate design is suggested. The two leaves are arranged in such a way that a jet issues at an angle toward the water surface through the opening between the two leaves. The bottom leaf remains fixed while the top leaf (control leaf) is moved up and down to regulate the flow. By using this arrangement, the high velocity supercritical stream is deflected away from the bed to the water surface. In addition to minimizing erosion, a lifting device of smaller capacity will be adequate for operating the control leaf. The existing regulators can be modified by adding an upward sloping sill just below the gate. The flow patterns, velocity decay, momentum decay, and bed-shear stress for different submergence and offset ratios are studied experimentally. The main characteristics of the deflected jet and the surface jet are also investigated and compared with those of the free and submerged jumps and surface jets. The new dissipator performs well in comparison with free and submerged jumps.