Question

A system of pipes conveying water is connected in parallel and in series as shown in section DE represents the resistance of a valve for controlling the flow, figure below. The which has a resistance coefficient KDE opening. where n is the percentage valve 左1 The friction factor f in the Darcy formula is 0.024 for all pipes, and their lengths and diameters are given by Length (mDiameter (m AA,B AA2B BC CD CF 30 30 60 15 30 0.125 0.15 0.1 The head at A is 100m, at E is 40 m and at F is 60m. If the valve is adjusted to give equal discharge rates at E and F, calculate the head at C, the discharge through the system and percentage valve opening. Neglect all losses except those due to friction. 10

please solve

Answer 1

Solution : we have Darcy's FoT mula to salculate due to tmiction. head loss LQL = KQ 2g ol where K-St 2dS For pipe AA' B→ KANB. 12x Co.)s 0.0 2 4 30 6000 For pipe煳AA28 → 2x (0.125) for pipe CD --o :024x15 12x Co. Kcp 60 o For pipe CF乡 kCF- 0.024x30 12X (0-1) For PiPe KpeC Resistance CAs AA18 and AA28 in paallel) KAS KAB 795 CS Scanned with CamScanner

Resisbance Ac CAB and B c n seies) MC- 2375 Head osS 'n ACHA -Ho lve hav-e Head loss in CF Hc -H 1500 Solving D and ② TCspectively 2.375 He-60 237S | He = 75.48 m QAc = o.lol6 m3/s Cs Scaned with CamScanner

Pipe cD and valve dE n series Hc-He 2 38.58 % Percentage value opening Head at c To ba Volume ow rate CS Scanned with CamScanner