Experimental Investigation of T-Jump Stabilization Using Water Jets and Sinusoidal Corrugated Beds

Hydraulic jump is a phenomenon that occurs in open channels with a sudden and rapid transition of the flow regime from supercritical to subcritical. One of the common approaches in controlling the energy dissipation of hydraulic jumps aims to expand the section of the stilling basin with the development of T-jumps. However, T- jumps without additional baffle and terminal elements are unacceptable for thorough energy dissipation. Therefore, this study investigates the main characteristics of T-jumps in an abruptly expanding channel and in the presence of bed water jets and sinusoidal roughness elements. Such complex configurations are hardly found in the literature. Inflow Froude numbers from 6.2 to 10.85, five relative jet flow rates from 0.10 to 0.27, and three rough beds with roughness wave slopes from 0.33 to 0.60 were selected. Experimental results revealed that increasing the bed corrugation would decrease the length of the jump, the length of the roller, and the sequent depth ratio. The same results were found in presence of bed water jets and sinusoidal roughness elements, but the T jump would appear to be better stabilized. In fact, it was also observed that increasing the relative flow rate of the jet had a significant effect in controlling the T-jump and reducing its relative length. The simultaneous presence of bed water jets and sinusoidal roughness elements decreased the relative length of the T-jump by about 81% and the tailwater depth by about 42% in comparison with the classic hydraulic jumps on smooth beds.