HYDRAULIC JUMPS PROPERTIES ON CORRUGATED BEDS

Abstract Hydraulic jumps have been used for dissipation of kinetic energy downstream of hydraulic structures, such as spillways, chutes, and gates. It was found that if jumps were made to occur on corrugated beds, tail water and length of jumps reduced significantly. The effects of corrugations on the basic characteristics of jump were studied for a different range of Froude number from 3 to 7.5. Five shapes of corrugations (sinusoidal, triangular, trapezoidal with two side slopes and rectangular) of the same amplitude and wavelength were tested. Two values of relative roughness t/y1 of 0.36 and 0.72 were studied. It was found that, for all shapes of corrugated beds, the tailwater depth required to form a jump was appreciably smaller than that for the corresponding jumps on smooth beds. Further, the length of the jump on the different corrugated beds was less than half of that on smooth beds. For the same amplitude and wavelength, it was found that the effect of the shape of corrugations is relatively small. The results of this study confirm the effectiveness of corrugated beds for energy dissipation below hydraulic structures. Finally, attempts were made to draw some conclusions from this experimental study.Research Center, Faculty of Engineering, King Saud Universit