Author(s): Jagilinki Aravind; T. I. Eldho

Linked Author(s): Aravind Jagilinki

Keywords: Hydrodynamics; Scour; Submergence ratio; Twin piers; Sediment transport; Particle Image Velocimetry; Horseshoe vortex

Abstract: This study examined the flow hydrodynamics around submerged twin in-line piers with varying submergence ratios at a constant spacing of three times of pier diameter, i. e., the face to face distance between the piers, focusing on the influence of submergence on mean velocity flow fields, flow patterns, and vorticity between the piers. The interaction between the twin piers significantly affects flow characteristics and sediment transport dynamics on a sediment bed, leading to variations in maximum scour depth and its distribution. Experimental investigation revealed that the submergence ratio is crucial in determining the flow velocity distribution and turbulence characteristics between the piers. Particle Image Velocimetry (PIV), an advanced instrument, was employed to collect time-series data along the channel centreline, and all experiments were conducted in the Hydraulics laboratory at IIT Bombay. The findings indicated that increased submergence can weaken vortex strength, leading to reduced scour hole formation. The strength of the horseshoe vortex is observed to be lower in front of the rear pier compared to the front pier, due to the sheltering effect. This research enhances the understanding of hydrodynamic interactions on rigid bed as well as scour characteristics in riverine environments, providing insights for submerged pier design to minimize the scour-related risks.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P2081-cd

Year: 2025