The effect of creating the surface waves on dredging of deposited sediments in rectangular water conveyance channels

Document Type : Original Article

Authors

Abstract
The goal of this paper is, considering the effects of creating the surface waves in a uniform flow on the bed load transport rate of deposited sediment in a primal rigid rectangular channel. Experiments were carried out in a rectangular flume of 10m length, 0.2m width and 0.3m height. The experiments were conducted for two gradations of sediments with median diameters of 0.34 and 0.48 mm, specific weight of 2.67, for five bed shear stresses (initiation of motion and it’s multiplies of 1.16, 1.25, 1.39 and 1.43 for median diameter of 0.34 mm and initiation of motion and it’s multiplies of 1.15, 1.25, 1.33 and 1.41 for median diameter of 0.48 mm), two wave heights (1 and 1.6 cm) and four different wave velocities. The results showed that creating surface waves generally increases the bed load transport rate. Furthermore, it was observed that for a given experimental parameters, the bed load transport rate increases with Strouhal number, dimensionless wave height and bed shear stress. It can be concluded that creating artificial waves can increase the bed load transport rate in a rigid rectangular channel up to 280% compared to the no wave conditions.

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  • Receive Date 30 December 2012
  • Revise Date 06 May 2013
  • Accept Date 06 June 2013