Question

Use the moody diagram provided. You have riveted circular steel pipe that is 1.5ft in diameter. The roughness is ε=0.003ft. Water at T=60^oF flowing through the pipe.

1. What is the relative roughness, ε/D, of the pipe?
2. What is the kinematic viscosity of the water in ft²/s?
3. What is the velocity for the Reynold’s number to be Re=1000? Ans 0.00811ft/s
4. What is the velocity needed for the Reynold’s number to be Re=30,000? Ans 0.243ft/s
5. What is the velocity for the Reynold’s number to be Re=2,000,000? Ans 16.2ft/s
6. Find the friction factor f for Re=1000?
7. Find the friction factor f for Re=30,000?
8. Find the friction factor f for Re=3,000,000? Ans ~0.0235

VALUE OF VD FOR WATER AT 60 F (V IN FPS, D IN INCHES) 01 02 04 06 08 1 4 6 810 2 05 05 04 010 008 002 GLASS DRAN DRASS COPPER, LEAD COMMERCAL STEEL WROUGHT IRON ASPMALTELD CASTRON 0001-0 ฉ2002-0.2006 0002 000 00630 0301 001 0030.03 41 02 0010 CAST IRON 0002 00010 LASTED ROCK TUNNEL 10 20 6810> 2 46810-2 46810 2 46810, 2 3收0,6 8w2 468洢 REYNOLDS NUMBER Re -VD

Answer 1

1. Calculate the relative roughness. 0.003 ft -0.002 D 15 ft 2. Kinematic viscosity of water at 60°F v= 1.210×10-5 ft2/s 3. VD Re-_ v (1.5 ft) 1.210x10 ft /s 100000 V= 0.0081 ft/s 4 VD 300001.5 ft) V (1.5 ft) 1.210x10-3 ft'/s V 0.243 ft/s

5. VD Re-_ 2,000,000l.5) V - 16.2 ft/s V(1.5 ft) 1.210x10-5 ft'/s 6. From the moody chart, at Re 1000 and0.002 f-0.064 From the moody chart, at Re 30,000 and0.002 f-0.02809 From the moody chart, at Re 3,000,000 and f-0.02348 0.002