Turbulence Intensity and Boundary Shear Stress in Meandering Compound Channel under the Influence of Sinusoidal Changes

Abstract

Compound channels are consisting of two hydraulic sections namely main channel and floodplain. In meandering rivers, with the passage of time and lateral movement of the meanders, the external bending progression and the sinusoidal or curvature is increased. The curvature of meandering sections can be defined by a dimensionless parameter as the sinusoidal number which is the ratio of meandering length of main channel to the floodplain length. In this research work, the hydraulic characteristics of flow including the velocity magnitude, boundary shear stress, turbulence intensity and turbulence energy of the main channel along the meandering compound channel have been investigated numerically, regarding changes in the sinusoidal ratio for six types of channels with different sinusoidal ratios. In order to investigate the effect of sinusoidal ratio in meandering compound channels on the hydraulic characteristics of the flow, the FLOW3D software is applied. Numerical simulation results show that by increasing the channel sinusoidal number from 1 to 1.641, the velocity and bed shear stress decrease and the turbulence intensity and energy increases. So that the maximum value of the above parameters occurs in the inner arc.

Keywords

• compound channel
• meandering
• sinusoidal no
• boundary shear stress
• turbulence intensity
• flow3d