Study on structure-induced flow and turbulence considering bed morphology

摘要

The study reported herein was conducted in a meandering like laboratory flume in order to determine near-bed flow and turbulent characteristics around river training structures with and without scour hole/deposition. Observation was performed near a couple of spurs placed in different part of the bend simultaneously. The purpose of this study is to evaluate near-bed three dimensional flow field, the turbulent stresses and the turbulent kinetic energy distribution around spurs with rough rigid bed as well as with developed bed morphology under similar flow condition. This study has revealed the distinctive characteristics of flow & turbulence quantitatively before and after the development of structure-induced bed morphology. Likewise, distinction in flow and turbulence near spurs placed in different part of the bend simultaneously was also investigated. Furthermore, a simple flow visualization technique was implemented to observe the generation and migration of vortices from the tip of the structure. A preliminary attempt was made to simulate the flow and vorticity field in near-spur region using 2D numerical model and validated with experiment on flow with spurs for rigid bed case as well.