Experimental Study of Flow Characteristics in Sluice Gates with Cylindrical Edges and Half-Cylindrical Edges

Sluice gates are widely used for water level control and flow measurement in open channels. The sharp edge of sluice gates causes low contraction coefficient (Cc) and limited flow rate capacity. Here, the performance of a new sluice gate which is consisted of a sharp-edged sluice gate and a drum gate (a sluice gate with a cylindrical end) is experimentally evaluated. Since the streamline leaves the gate more smoothly, Cc is considerably increased. i.e., from 0.6 in sharp edged gates reached to 1.0 in cylindrical-edged gates. Moreover for a given upstream depth, this gate was less likely to become submerged compared to an equivalent sharp edged sluice gate. For upstream water depth of gate to opening of gate(H0/W) in range 4-18,tailwater depth to opening of gate( yt/W) increased up to 22 percent for drum diameter of 63, 90, 125 and 200 mm. This feature obviates the need to increase the free board height in the upstream channel and refrains from upstream overflow whenever unexpected downstream tail water rise occurs. Moreover, distinguishing condition curves for these gates were obtained.