Influence Of Limited Vegetation Near River Banks On the Flow of Open Channels

In this study, a grouped piles were arranged in inline as limited vegetation near river banks, and the corresponding flow and turbulence characteristics in a rectangular open channel flow were investigated using a numerical approach based on the k-ω SST model.The case study concerns an 8x8 cylinders, with patch length of the grouped piles of L=B=12D, a spacing ratio of P/D = 1.5 and a Reynolds number of 650.The flow and turbulence behavior in the mainstream, and on both banks of the channel were observed.When the flow crossed the patch length of grouped pile, the mean streamwise velocity at the downstream was reduced.However, in the opposite bank, and in the mainstream, the mean streamwise velocity and turbulence kinetic energy (TKE) were slightly increased.The results revealed firstly, that the grouped piles are useful to protect the riverbanks from higher velocities and turbulence effects comparing with the non protected riverbanks.And secondly that the RANS approach provides a satisfactory level of predictive accuracy for engineering applications.