Laboratory Investigation The Effect of Porosity of Permeable Obstacle on Control of Gravity Current

Gravity current is a phenomenon caused by density difference between two fluids and due to this phenomenon the fine sediments can be moved to the body dam and as a result causes for many serious problems for dam intake. Therefore, controlling the flow can reduce the potential problems. In this study a permeable obstacle was used to evaluate the performance of permeable obstacles for control of turbidity current. The variables were the porosity percentage of the obstacle and different concentrations of the currents. The gravity current discharges and concentrations were measured upstream and downstream of the obstacle. The results of the measured discharges showed that the obstacle efficiency in control of gravity current reduces with increasing porosity. The results of the measured concentrations also showed the same conclusion. The final results of the review sediment load and view similar trend was confirmed. After calculating water entrainment to the gravity current passing through the permeable obstacle, it was observed that with increasing porosity of permeable obstacle, the volume of water entrainment is reduced. Therefore it can be concluded due to lower volume of water entrainment, processing efficiency in controlling the gravity current using the permeable obstacle is reduced. Also, the maximum efficiency of the controlling the gravity current was measured about 73.2%.