Role of Grouped Piles on Flow Characteristics Around Impermeable Spur Dike.

In this research, the impermeable spur dike combined with grouped piles were arranged as two spur dike patterns (L and T), and the corresponding flow and turbulence characteristics in a rectangular open channel flow were investigated using a computational fluid dynamics (CFD) numerical approach based on the standard k - ε model. The patch lengths of the grouped pile were varied between 0.2 and 0.6 m around the impermeable spur dike, and the flow and turbulence behavior near the spur dike tip, in the mainstream, and on both banks of the channel were observed. When the patch length of grouped pile increased to 0.6 m, the increasing trend of mean streamwise velocity at the downstream was reduced up to 5% in the left bank, 52% in the right bank, and 8% in the mainstream. The tip of the spur dike turbulence intensity (T.I), turbulence kinetic energy (TKE), and mean streamwise velocity reduction were 19%, 35%, and 12%, respectively. The results revealed that both the spur dike patterns (L and T) are useful to protect the riverbanks and the spur dike tip suffering from higher velocities and turbulence effects comparing with the typically impermeable spur dike. [ABSTRACT FROM AUTHOR]