Question

1. a) 1 m of water is flowing through a pipe in 10 minutes. The diameter of the pipe is 1.5 cm. Calculate the velocity of the water inside the pipe. 2. b) The pipe is extended to a bending and an elbow system. The head loss for bending and elbow system is 500 mm and 900 mm respectively. Calculate the loss coefficient for both the systems. Which one has higher loss coefficient and why?

Answer 1

• Answers : (a) velocity (V) = 9.4 m/s2  
• (b) : The loss coefficient for bending = 0.11 and for elbow is = 0.2
• JUSTIFICATION (for b): The loss coefficient for elbow is greater than that of bending, becuase the head loss due to bending and elbow depends on the angle of (curvatur or  bend angle ) for the elbow in the given question has curvature angle must be lesser than that of bending. The lower bending angle (like 90 degree) restric the flow it leads to head loss. (greater the head loss greater the value of loss coefficient K )

- a) Given datas- Flow volume = 1m3 . Flow tooli Rate CQ) m) lononuudes. Q = Oolm | minutes. Tol mi/sec 10 - 0.00166 m3/sec de 1.5CM = 0.015m. A (Area)= I (20.015)2 = 1.76x109 m² Now, calculating velocity, with the help of continuity equation. 0= A.V. 0.00166 = (1-768104) xv. Tv: 9.4 m/sec) b) Mow, calculating for Loss coefficient bend & Elbow (k) :- hegend = K ( 243 ) g= gravity = 9.81 m/s2. 0.5 = K (69.472) ve velocity (2x9.81) ka loss coeff. her head loss due to - Bend . hB = 500 mm Ik = o.ll] 20.5m. Loss coefficient (K) for Bending is2011 (2x9.80(0.52 -EK. (9.472

Now, For Elbow. he = K (ou Og Ek (49.42 (0.42 (2x98)) aki (9.472 kaor] for Elbow is greater The loss than coefficcient Bending.