Analytical and Experimental investigation of Hydraulic Jump Characteristics on Permeable Beds

In this research, the effect of channel bed permeability on the hydraulic jump characteristics is investigated. At first, through analyzing the momentum equation, a new equation for direct calculation of the sequent depth ratio for permeable beds obtained. Then, using a channel 6 meters long and 80 centimeters wide laboratory channel, a series of experiments over permeable porous beds with different gran size distribution and different length and width were conducted. The Froude number ranges from 5.3 to 7.4. It was observed that over the permeable bed, the analytical equation estimates the sequent depths ratio better than the Blunger equation and also the sequent depths changes show more dependency on the Froude number in comparison to the bed permeability. The results also showed that permeability of the bed reduced the sequent depths ratio and the jump length significantly compared to the impermeable smooth bed and also increased the energy loss caused by the jump.