Question

Joule - What is the difference between static mic, d al wees for fund flow? How can we measure these types of pees? - Water flows in a pipe network between two w a factory is a certains part of the pipe system the flow is 295 There is where we changes in the pipe as illustrated in the next figure. The pipe dishes the water flow at meshee Calculate the next parameters 1. The major and minor losses for the system? 2. What is the pressure needed to keep the few steady in the system? 3. What can be done redisce the losses in the system? - bh cdrc = D - 15 cm 1500 m smooth pipe e = 0.5 officient TTTTTT Contractions 0.8 O 0.2 0.4 0.6 Area at AR Adapted from Ford McDonald, Introduction to eld

Answer 1

Major wss = f 1 2 3 4 lo-6 10-6 15 fa Darcy fructor (from Moody's diagram) Reynods No Re = VIDI - 1 66940.15 = 2.5x105 for pipe 1 Re - VIDI = 11 C = V2 D2 - 0.4038+0.305 = 1.23x10 " "2. Relative roughnen & = 0.5 = 0.033 for pipe 1 & - 05 = 0.0164 for pipe 2. : fi = 0.06 fa = 0.048 May or loss a f, hou vang & fr. 22 h 30.15 = x 0.0 6 x 500 0.15 lbla2 1.6692 + 0.048 x 1000 2x 9.81 0.305 0.40382 2 x 9.81 = 28.395 + 1.308 = 129.703 m Minore loss - KL1V2 + . Kw V2 + 1 x 0.40382 = 0.5x 1.6692 2x 9.0 2x9.81 0.0793 m i Total head loss = 29.703 + 0.0793= 29.7823 m (hu) Apply Bernoull's equation between the weations 2 2 29, 7823 + - 1.6692 2x 9,81 – 29.6486 0. 40382 2x9.21 og = P = 101325 & 290853.1 = 392178. 1 Pa = 1392, 178 keer P2 = Patm = 101325 Pa
If smooth pipe is used then Darcy friction factor would be less than 0.01 and that would reduce major loss by a large margin.

The calculated pressure P1 is the absolute pressure.

Here apart from expansion loss, exit loss (taking sharp edges) is also considered for minor loss.