Distribution of turbidity in flow constrained by transverse dam

Abstract

Construction of control structures in rivers allows to manage channel flow in required direction and artificially change its natural condition providing rational interaction of flow and channel. Redistribution of both liquid and solid flow occur under influence of control structures. The main goal of the given work is to set the distribution pattern of turbidity in flow constrained by transverse blind dam. For the first time the task is studied with the use of field research data from dam No.30 in Amudarya river. The location of section and verticals in choosing turbidity samples, the sections are set based on the hydraulic structure of deformed flow. Flow division scheme has been proposed for hydraulically homogeneous zones of weakly disturbed core, intensive turbulent mixing and backflow, as it is accepted in the theory of turbulent flow with mixture spreading in a confined space. For the verticals the samples were taken in two depth points 0.2H and 0.8H, and areas with shallow depth – at 0.6H. Turbidity distribution by depth in weakly disturbed core has the shape of a “boot” and μ 0,8H is 2-3 times higher than μ0,2H . The rest are close to logarithmic. The maximal turbidity at 0.8H is 3.6 kg/m3. Turbidity distribution in layout in the zone of intensive turbulent mixing is affine and comply with Shlihting-Abramovih’s theoretical relationship for starting point. The obtained results can be used in future to forecast interdam area sedimentation and new bank line borders.