Author(s): Nishank Agrawal; Ellora Padhi

Linked Author(s):

Keywords: Scouring; Meandering channel; Spur dyke; Dyke orientation; Low flow velocity

Abstract: In geophysical flows, the channel often starts to meander when it encounters a plan terrain. Owing to higher flow velocity, it tends to erode the channel boundary (bed and banks) that comes across its path. Scouring in a meandering channel primarily depends on channel boundary, flow condition, and sediment properties. To date, numerous works have been conducted to understand the velocity distribution and scouring pattern in a meandering channel under varying discharge conditions. However, only a handful of work has been reported on the scour pattern under low discharge conditions in a meandering channel. Therefore, in this paper, an experimental study was conducted under a very low discharge in an 80° (central angle θ) bend to analyse the scour pattern. Investigation of the scour profile reveals that maximum scour occurs at the downstream side of the bend apex rather than the bend apex. Hence, an attempt has been made to counter the scour using the spur dyke. In doing so, a non-submerged spur dyke was installed at three different locations θ = 0°, 40°, and 60° of bends with three orientations α = 60°, 90°, and 120° for approaching and developed flow conditions to identify the best location and orientation of the spur dyke. Observation suggests that spur dyke at θ = 60° with α = 90° and spur dyke at ‘θ’ = 40° with ‘α’ = 60° provide the best results for approaching and developed flow conditions, respectively, in terms of preventing scour under low flow velocity.

DOI: https://doi.org/10.26077/60b8-4263

Year: 2022