2025 Volume 81 Issue 16 Article ID: 24-16039
Secondary flow of the second kind is ubiquitous in real rivers and is considered to coexist with secondary flow of the first kind caused by centrifugal forces. Therefore, Secondary flow of the second kind may have a significant influence on sediment transport patterns, including scouring near riverbanks. However, the importance of Secondary flow of the second kind has not been paid much attention in actual rivers, and they have been neglected. In this study, in order to clarify the importance and role of secondary flow, numerical experiments were conducted in a rough open channel turbulent flow field with a small aspect ratio, where secondary flow is dominant. The results indicate that the secondary flow velocity in a rough-surface open channel is much larger than that in a smooth-surface open channel, and that the motion of particles is greatly influenced by the instantaneous flow velocity.
