CHARACTERISTIC OF CONTRACTION AND DISCHARGE COEFFICIENT FOR FLOW UNDER SLUICE GATE

Abstract

The contraction coefficient (Cc) and discharge coefficient (Cd) always rise in flow

while sluice gate operated with variation of open gate and discharge (Q). This experimental re- search used prototype model made from fiberglass (horizontal channel), sluice gate installed on it.

Two models of trapezoid baffle block installed as three rows, specified location 25 cm after sluice

gate pair using sill with different dimension. Water depth (y) and velocity (v) were measured dur- ing each running test then Froude number, contraction coefficient (Cc) and discharge coefficient

(Cd) were calculated. The result showed that trapezoid baffle block model T2 (used no sill, sill 2 cm and sill 2.7 cm, Fr = 0.11 - 0.75) gives the better performance modelling of Cc and Cd in term of the initial Froude number with R2 = 0.8086 (Cc) and R2 = 0.8273 (Cd).