Question

Question 1 50 marks Part A (30 marks) In a proposed water supply system, two large reservoirs will be connected with a pipeline 9 km long and with an elevation difference of 72 metres between the full water levels of the reservoirs. The pipe will be required to convey a minimum discharge of 450 L/s. The proposed pipe material is UPVC. Fittings in the pipeline include one 90° short radius elbow and one gate valve fully open. Pipeline entrance and exit types with the walls of the reservoirs will be flush. The pipe used is Class 10 UPVC pipe (Max allowable pressure of 1000 kPa) that comes in the sizes specified in Table 1. Table 1 Nominal and internal pipe diameters T Nominal diameter (mm) 450 500 560 630 710 800 Internal diameter (mm) 395.9 439.9 4 92.7 554.4 624.6 703.9 Determine the required pipeline diameter to convey the design discharge between the two reservoirs using available pipe internal diameters specified in Table 1. After selecting your pipe diameter, calculate the actual discharge that will occur. Use the Moody diagram and the Darcy-Weisbach equation to complete this design, and submit a clearly marked copy of the Moody diagram along with your submission. Part B (20 marks) Using the longitudinal profile of the pipeline shown in Table 2, calculate the energy grade line and the hydraulic grade line and plot against the longitudinal profile of the pipeline. Determine the maximum and minimum pressures in the pipeline. Comment on the suitability if the Class 10 pipeline for this application. Provide a table and plot of your results. Your plots may be either hand drawn or computer generated. ENV2103 Hydraulics 1 Assignment 2, 2020 Question 1 continued Table 2: Longitudinal profile of pipeline Chainage (m) Om Om RL (m) 102 m 96 m Pipeline Item Water level in the upstream reservoir Entrance from the upstream reservoir and fully open gate valve 90° short radius elbow Pipeline exit to the downstream reservoir Water level in the downstream reservoir 4200 m 9000 m 10 m 27 m 9000 m 30 m Hint 1: PEQ 5.13 from the study book should be attempted before calculating the energy grade line and hydraulic grade line. Hint 2: Make sure you use your final discharge in the calculation of the energy grade line and hydraulic grade line.

Answer 1

Grevess Q = =qkm, h=72 m D = ? 450L/s = 450X co 3 m3/5 -9 kn masor he five Loss h = fa 2g D. 18 A= 7.2 h = 22 g D E6 flo² 7 g D5. 8fto2 72gD5

Assume con efficient of friction for pope materid 0.012. Fordon factor -461 0.048 8 fL p² 72 - 8 x 0.048 X 9000 x 22 N ² X 9.81 X DS 728404849000 x 450x763)2 2x 9.81 Xos 6971.09 X05 = 699.84 oss 0-1003917 D = 0.631 m Do 637.45 mm 630 554.4 710 624.6 Hence At 631.45 mm Alo to table BY anterpolation method. 554. 4 t 6246-554.4. X (631.45 71 - 630 - 630 ) - 555 67 Hence Nominal diameter 631 45 mm goternal diameter 555:67 mm And