Ali Akbar Akhtari

The aim of this paper is to study the effect of middle vanes on the flow structure in open-channels with sharp 60° bends. For this purpose, two cases are considered, i.e. bends with (one-vane case), and without (no-vane case) middle vanes. To minimize the systematic errors, the models are also numerically simulated using the Standard and RNG based k-ε turbulence models. The validation process shows satisfactory agreement between the measured and predicted results with average RMSEs of 0.18 and 4.82, for the water depth and velocity values, respectively. The comparison of the obtained results for the no-vane and one-vane cases is presented. It is found that middle vanes are efficient to minimize the intensity of secondary currents, super-elevation, and the tendency to flow separation in the convex bank of the bend. According, non-submerged vanes can help to reduce erosion and sedimentation the bend.