Turbulent Characteristics of the Stratified Flow in the Braided River with Two Symmetrical Anabranches

Abstract

The turbulent characteristics of stratified shear flow in braided rivers have not been known until now. The physical model experiment was conducted to study the turbulence kinetic energy distribution of stratified shear flow in the typical braided rivers with a mid-bar between two symmetrical anabranches. Firstly, the distributions of depth-averaged turbulence intensity components in different sections of the anabranch were analyzed. The turbulent intensity peak occurs at the boundary of the separation zone near outer bank and the high velocity zone near inner bank in the entrance region of the anabranch. In the outlet section of the anabranch, turbulent intensity increased at the inner bank. Secondarily, Lateral-averaged turbulence intensity components were compared between different sections. There was obvious high turbulence appearing at the interface of hot and cold water in the inlet section of the anabranch. Finally, the distributions of total turbulence intensity were analyzed by the sectional contours.