Author(s): K. Ansari; H. P. Morvan; D. M. Hargreaves
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Keywords: Trapezoidal; Open channels; Bends; CFD modelling; Boundary shear stress; Division line; Secondary currents
Abstract: In spite of the practical relevance, as most rivers follow a winding course, relatively little experimental or numerical work has been done on the open channel flow inside a bend. The present paper aims to extend the findings of Cacqueray et al (2008), Morvan and Hargreaves (2009) and Ansari et al (2010) through numerical analysis on the distribution of shear stresses on the bed and sidewalls of trapezoidal channel sections having bends, using CFD approach. The commercially available CFD software ANSYS-CFX version 11 (2008) is used for the purpose. Simulations are run on channel sections having straight portions before and after the bend, as the asymmetry in flow starts well before the curve and the flow take significant length to recover after passing a curve. The impact of the variation of the slant angle of the sidewalls on the shear stress distribution is also analysed. The division lines are plotted at different channel sections inside the curved portion for the analysis of the distribution of shear on bed and sidewalls separately. The results are compared with available literature and give good insight in to the flow movement inside a bend.
Year: 2010