EFFECTS OF GROIN PERMEABLE ON FLOW VELOCITY

The Roughness in the open channel are inhibiting factor which depends on the amount of resistance characteristics such as the roughness of channel. This paper investigates the vertical piles in the flow through the open channel which act as hydraulic roughness affecting the flow behaviors. The purposes of this research are to study the reduction coefficient that affects the magnitude of flow velocity in the open channel due to the resistance of vertical piles. The Research based on the influence of the vertical piles to the flow has been studied by previous researchers. The results of those studies explained that the vertical piles can reduce the flow velocity due to the increase of the shear stress (). This research uses the structure of the model structure vertical a pile in 2D open channel with the width of channel is 0.6 m and the length is 10 m. The distance between the model structures is determined as two times length of the model structure (2L) and the distance between the vertical piles (G) is 0.7 cm.. The results showed that with the arrangement of the vertical piles, flow rate is reduced compared to the conditions of open channel without a vertical pile structure. The shorter the distance between the pile and the bigger the pile diameter to be used, the smaller the Chezy coefficient is become. Therefore the resistance becomes bigger then the velocity reduced