SEN 744 Water Supply and Wastewater Removal - Assignment 2 Problem 1 In the water supply system shown in Fig. 1, water is pumped from the ground reservoir to the Village ABCD (elevation 120.00 m) through the water main PA. The value of C for all pipes is 100. A water meter located on pipe DC indicates a flow of 20 L/s. The following network data are provided: Pipe dia (mm) L (m) PA 450 8,000 AB 200 800 AC 250 600 AD 200 700 BC 200 800 CD 150 1000 Fig. 1 Water System for Problem 1 (a) Determine the flow in each pipe as well as the flow delivered to point C (Qc) (b) Calculate the pumping head, if the residual pressure at point C is not to be less than 200 kPa (20 marks) Problem 2 The water supply system shown in Fig. 2 is designed to serve a small town ABDCA. The flow from the reservoir is delivered to the town by gravity through the 400 mm main. All pipes have a Hazen-Williams C of 100. (i) Assuming an initial flow of 50L/s (clockwise direction) in BC, determine the flowrate in each pipe. Iterate your solution up to a correction of 0.5 L/s. (ii) What is the flow in the mains from the reservoir to ABCD? Fig. 2 Water Network for Problem 2 (20 marks) From Reservoir 20 L/s 60 L/s 55 L/s 25 L/s 200mm, 2000m 150mm, 1000m 250mm, 1000m 220mm, 1000m A (Elev = 100m) B (Elev = 110m) C (Elev = 80m) (Elev=80m) D (Elev = 110m) 400mm Problem 3 A circular gate 4m in diameter is to be placed on the incline of a reservoir as shown in Fig. 3. The gate rotates about a shaft installed on an axis parallel to the water surface and long its diameter (see figure). Given that the free surface is 10m above the shaft, (i) what is the magnitude and location of the resultant force by the water acting on the circular gate? (ii) what is the moment about the shaft? 4m diameter circular gate shaft 10m reservoir 60o