Question

An inclined circular gate controls the flow of water across a storage structure (see Figure 1). The gate is 1.0 m in diameter with water on one side. Determine:

1. the total resultant force acting on the gate
2. the location of the center of pressure

the resisting moment at the pivot or hinge (if located at the upper edge of the gate).

Question 1 An inclined circular gate controls flow of water across a storage structure (see Figure 1). The gate is 1.0 m in diameter with water on one side. Determine (a) the total resultant force acting on the gate (b) the location of the centre of pressure (c) the resisting moment at the pivot or hinge (if located at upper edge of the gate) 60° 1.5 m sin 60 1.5 m Vep sin 60 m C.g уср c.p Figure 1: A circular gate installed on inclined side of a water storage structure

Answer 1

(a) Total resultant force acting on the gate F_R = rho g h^- A F_R = 1000 (9.81) (1.5 + 1/2 sin 60) times Pi/4 (1)^2 F_R = 14885.84 N F_R = 14.885 KN (b) location of the centre of pressure. h^-_c.p = h^-_c.g + I_G_xx sin^2 theta/A h^- = (1.5 + 1/2 sin 60) + Pi(1)^4 (sin 60)^2/Pi/4 (1)^2 (1.5 + 1/2 sin 60) h^-_c.p = 1.9572 m y^-_c.p = 1.9572/sin 60 = 2.26 m c) moment + (m) = F_R (2.26 - 1.5/sin 60) = 14.885 (0.528) M_R = 7.859 KN.m