Experimental Study on the Effects of Artificial Bed Roughness on Hydraulic Parameters of Saline Density Currents

Turbidity currents are often the main process for the transport and deposition of the sediments in narrow, alpine reservoirs. In this research, 63 experiments were performed to investigate artificial bed roughness effects on the saline density currents. Conic and Cylindrical shapes roughness with three heights were used. Velocity and concentration profiles were measured in 4 and 3 cross-sections, respectively. The results show that as the roughness height increases the velocity decreased and the density current body thickness also increased. Furthermore for a constant Gradient Richardson number by increasing roughness height, the coefficient of entrainment was also increased. In the some experiments a special behavior was seen which effects on the velocity profiles. This behavior was named “Lifting phenomenon”. This phenomenon was observed when blockage element is more than 10% and 14% for Cylindrical and Conic shapes, respectively.