### 4HE Fluid Mechanics April 2000

Part A (20 x 2 = 40)

1. What is Newton's law of viscosity?
2. State the similarity laws
3. What is potential flow?
4. State the type of fluid in the following cases:
(a) Rubber latex
(b) Bentonite clay
5. Define equivalent diameter of pipe
6. Distinguish between form drag and skin drag
7. Define Mach number
8. What is the relation between maximum velocity and average velocity in laminar flow and turbulent flow
9. Draw velocity profile for laminar flow in a circular pipe
10. Compare and contrast venturi meter and orifice meter
11. What is the principle of working of pitot tube?
12. Give examples of area and head flow meters
13. Define porosity and minimum fluidization velocity
14. Draw the drag curves for regular solids
15. State Ergun's equation and its application
16. Define boundary layer
17. What is meant by NPSH?
18. Compare centrifugal pump with reciprocating pump
19. List the various losses occurring in centrifugal pump
20. Write the filed of application of various flow meters
21. Part B (5 x 12 = 60)

22. In a chemical reactor of 10 m tall, the density of fluid mixture varies with the distance 'y' in meters from the top of the reactor as
23. r = 1000[ 1 + y/50 + (y/100)2]

Assuming the mixture to be effectively stationary, determine the pressure difference between the top and bottom of the reactor.

Or

24. The performance of an oil rig consuming a discharge Q of oil depends on the internal diameter d of the rig, the rotational speed N of the shaft, the mass density r, the dynamic viscosity m, the surface tension s and the specific weight w of the oil. Show by dimensional analysis
25. 26. State and prove the Bernoulli's theorem for incompressible fluid and indicate the corrections necessary for its application
27. Or

28. Water at 60oC is pumped from a reservoir to the top of a mountain through a 15 cm pipe at a velocity of 3.5 m/s. The pipe discharges into the atmosphere at a level of 1000 m above the level in the reservoir. The pipe itself is 1500 m long. If the overall efficiency of the pump is 65%, calculate the power requirement.
29. An orifice meter having an inside diameter of 2.5 cm is located in a 8 cm pipe. Water is flowing through the line and the mercury manometer measures the differential pressure over the instrument. The leads are filled with water. When the manometer reading is 35 cm, what is the flow rate of water per minute?
30. Or

31. (a) Explain the working of a rotameter with a neat sketch. (6)
32. (b) Explain the method of functioning of a magnetic flow meter. (6)

33. Derive Ergun's equation and state its usefulness.
34. Or

35. What is continuous fluidization? Explain how and where it is applied? Briefly state the design steps for a system using continuous fluidization.
36. (a) Discuss the factors to be considered for selecting a pump for an operation. (5)
37. (b) With a neat sketch explain the working of a centrifugal pump. (7)

Or

38. Write short notes on:
(a) Compressors and blowers
(b) Fans
(c) Diaphragm pumps