Hydrodynamic Performance of Triangular Winged Bandal-like Structure in a ۱۸۰-degree Bend

This experiment was conducted in order to determine the hydrodynamic performance of a Triangular Winged Bandal-Like (TWBL) structure, which is a combination of the Bandal-Like (BL) structure and Triangular Vane (TV). For the purposes of this study, the JFE ALEC magnetic velocity meter was used to measure the three components of flow velocity under non-submerged hydraulic conditions at a Froude number of ۰.۲۴. The three considered cases for this measurement were the non-structured case and the BL and TWBLs. The results showed that the flow deviation occurred through the impermeable upper part of both structures towards the middle of the channel. At downstream of both structures, bubbling flows were caused by the collision of upward flows with the near-surface flow, causing disturbances in the latter. Both the BL and the TWBL structure reduced the secondary flow strength along the bend within the structure range. Compared to the BL structure, the TWBL structure reduced the secondary flow strength by about ۲۰%, which indicates the weaker inclination of the secondary flow toward the outer bank in the TWBL structure. The relative maximum shear stress in the TWBL structure is on average ۱۷% lower than that of the BL structure.

Keywords:

Flow pattern , Karun River , Meandering river , Secondary flow strength , Shear stress.