Author(s): R. N. Siqueira; K. Shiono

Linked Author(s):

Keywords: Secondary current; Compound channel; Stratified flow; Vorticity balance

Abstract: The occurrence of secondary flow at the junction of the main-channel and the flood-plain in a compound channel considerably increases the exchange of momentum and mass around this region. The secondary flow that is initially created due to anisotropy of turbulence affects the longitudinal velocity, altering the shear stress distribution and also the density distribution. For homogeneous density flows, the anisotropy of turbulence is said to be the main contributor to the secondary current generation. But for the narrow compound channel investigated in this work, it was found that the shear stress can also contribute to the generation of secondary flow. For a density stratified flow condition, density gradients can also affect the vorticity balance and therefore produce secondary currents. The importance of generation mechanisms for secondary flow under homogeneous and stratified density conditions in a compound channel is analyzed in this study. It was found that although the anisotropy of turbulence is the one of the main contributors to secondary currents generation, the shear stress and lateral density gradients also contribute to the vorticity balance and therefore are important parameters for the production of secondary currents.

DOI:

Year: 2003