Investigating the Effect of Channel Bend Radius on Flow Characteristics in Inclined Bed Channels

Articles in Press

Document Type : Research Paper

Authors

1 Assistant Professor in the Department of Hydraulic Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz ,, Ahvaz, Iran

2 Professor in the Department of Hydraulic Structures, Faculty of Water Engineering and Environmental Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran

Abstract

Meanders in rivers are critical areas for studying flow patterns. Flow within river bends is influenced by centrifugal forces and pressure gradients. Given that rivers exhibit various bed slopes, studying the three-dimensional flow pattern in such channels is of significant importance. The objective of this study was to investigate the three-dimensional velocity components of flow in gentle and sharp 90-degree bends with sloped beds. Experiments were conducted in a channel with central curvature radius-to-width ratios of two, four, and six. Velocity measurements were performed using the Vectrino velocity meter, one of the most advanced instruments for measuring flow velocity. The results indicated that due to the effect of the water's weight component along the bed slope, the maximum longitudinal flow velocity in the initial sections of the bend for gentle bends occurs near the outer wall. However, in the later sections, it shifts closer to the middle of the channel width. Across all Froude numbers and all bends, the transverse velocity profile could be divided into two layers: one near the outer wall of the bend with maximum velocity and another near the inner wall of the bend with minimum velocity, located at 25% of the channel width. It was also observed that by doubling the Froude number from 0.05 to 0.1, the location of maximum shear stress extended from the range of up to 30 degrees to the range of up to 50 degrees of the bend section, and was concentrated near the outer wall.

Keywords

Main Subjects

Iranian Journal of Soil and Water Research

Articles in Press, Accepted Manuscript
Available Online from 24 December 2024

Files

Share

How to cite

Statistics