Effect of Channel Bed Corrugations on Hydraulic Jumps

Abstract

There have been many investigations on the effect of roughness elements on physical parameters of hydraulic jump. In practice, baffle blocks and sills are commonly being used to stabilize the location of a jump and shorten the length of a stilling basin. On the other hand, corrugations which cover the entire length of the basin may be an alternative. In the present study, hydraulic jumps on corrugated channel beds are studied experimentally. Values of 0.20 and 0.26 were used as the wave steepness of corrugations in the experiments. The range of Froude number was between 5 and 12. The tailwater depth-initial depth ratio was determined as a function of the Froude number. The length of the jump and the energy dissipation occurring in the jump were also determined. The results are compared with the data available in literature for corrugated beds and those of the hydraulic jumps forming on a smooth channel bed. It was determined that the tailwater depth required to form the jump and the length of the jump on corrugated bed were appreciably smaller than those of the corresponding jumps on a smooth bed. It was also found that the head loss for jumps on corrugated beds were higher than those occurring on smooth beds and corrugations were efficient in stabilizing the location of the jump. Therefore corrugations should be considered as an effective alternative of accessory devices such as baffle blocks and sills.