Unveiling the Dynamics of Hydrosuction Sediment Removal: Insight into Flow Characteristics, Flow Profile, and Critical Suction Velocity

Abstract

This study aimed to investigate the critical suction velocity required for lifting sediment off the bed under hydrosuction. Flow characteristics below the suction pipe under unbound and bound conditions were studied experimentally and numerically, and the effects of various parameters on the critical suction velocity, such as suction pipe diameter, suction discharge, suction inlet height, and sediment size, were investigated. The results showed all the parameters significantly affect the critical suction velocity, with suction inlet height being the most influential. Unbound and bound conditions yielded divergent flow characteristics beneath the suction pipe, revealing distinct flow patterns. Interdependency among the parameters affecting critical suction velocity have been studied statistically, and empirical relations are developed to compute the critical suction velocity, its resultant centerline velocity, and the associated flow profile. A proposed relation for critical suction velocity showcased a ±10% error margin, while equations computed resultant centerline velocities and flow profiles with ±15% accuracy, representing satisfactory agreement. These findings can also be helpful in designing efficient suction systems in various sediment-laden water environments. The current study on hydrosuction sediment removal presents practical solutions for addressing the persistent challenge of reservoir sedimentation. Hydrosuction is an efficient and cost-effective method of sediment removal with minimum disturbance to the connecting structures and surrounding ecosystem and aquatic life, ensuring sustainable reservoir management. The study focuses on providing detailed insight into the behavior of the flow below the suction pipe under varying conditions, which is responsible for sediment movement during hydrosuction. The study also investigates the minimum suction velocity required to lift the sediment off the bed surface. Applicability of hydrosuction is not limited to the desilting of a reservoir; it also holds potential for various applications in multiple fields, such as river and canal restoration, dredging of navigational channels, irrigation canal cleaning, dewatering and slurry removal, contaminant cleanup, trench excavation, flood control, and wastewater management.