Analysis of Turbulent Flow Characteristics Around Bar using the Conditional Bursting Technique for Varying Discharge Conditions

摘要

Braided river is currently important topic of study; several scientists doing research on the complexity of braided river. However, the turbulent characteristics of flow around the braid bar is not thoroughly studied till now. In the current paper, the quadrant method is used for analyzing the turbulence characteristics of flow in the vicinity of bar using 2-D bursting events technique. Although many advances have been made within recent years in interpreting the mechanics of flow, transport of sediment and sedimentary architecture of braided rivers, many key issues remain to be addressed in particular the underlying processes of braid bar initiation. An attempt has been made herein to relate the depositional characteristics around the bar in the braided river model to the sweep and ejection bursting events. The concept of the hole is used in order to isolate the extreme events that contribute to the turbulent burst. The mean angle of sweep and ejection events possesses direct relationship with the scouring/ deposition characteristics in the vicinity of bar. The mean values contour of normalized ejection and sweep stress are plotted and their variation with the changing discharge is studied in this paper.