CE 1208 FLUID MECHANICS AND MACHINERY (AS PER THE LATEST SYLLABUS OF ANNA UNIVERSITY ) PART A ANSWER ALL THE QUESTION 10X2=20 1. A flat plate of area 1.5X106 mm2 is pulled with a speed of 0.4m/s relative to another plate located at a distance of 0.15mm from it. Find the force required to maintain this

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CE 1208 FLUID MECHANICS AND MACHINERY

(AS PER THE LATEST SYLLABUS OF ANNA UNIV
ERSITY

)

PART A



ANSWER ALL THE QUESTION


10X2=20


1. A flat plate of area 1.5X106 mm2 is pulled
with a speed of 0.4m/s relative to another
plate located at a distance of 0.15mm from it. Find the force required to maintain this
speed, if the fluid separating them is having viscosity as 1 poise.

2. State the Continuity equation for compressible and inc
ompressible fluids.

3. Define hydraulic grade line?

4. Write the Darcy
-
weisbach equation used to find loss of head due to friction in pipe.

5. What do you mean by dynamic similarity?

6. Define Weber's number?

7. A turbine develops 7225 kW power under a hea
d of 25 m at 135 rpm. Calculate the
specific speed of the turbine and state the type of the turbine.

8. Define specific speed of a turbine?

9. What is negative slip? How it occurs?

10. What is meant by suction head and delivery head?




PART B





ANSWER ALL THE
QUESTIONS:


5X16=80


11. (a) If 5.27 m3 of certain oil weighs 44 kN , Calculate the specific speed , mass density
and specific gravity of the oil. (6)

(b) What ar
e the physical phenomena which are responsible for the property of viscosity?
How these factors contribute to viscosity of fluid? (4)

(c) A body weighing 441.5 N with a flat surface area of 0.093 m2 slides down lubricated
inclined plane making a 30° angle
with the horizontal. For a viscosity of 3 m/s ,
determine the lubricant film thickness. (6)


12. State and prove the Bernoulli's Equation and write the applications of Bernoulli's
Equation. (16)


13. Derive an expression for Darcy


weisbach formula to det
ermine the head loss due to
friction. Give the expression for relation between friction factor 'f' and Reynold's number
for laminar and turbulent flow. (16)



14. A30 cm diameter pipe, conveying water, branches into two pipes of diameters 20 cm
and 15 cm r
espectively. If the average velocity in the 30 cm diameter pipe is 2.5 m/s, find
the discharge in the pipe. Also determine the velocity in 15 cm pipe if the average
velocity in 20 cm pipe is 2 m/s. (16)



15.The pressure difference ?p in a pipe of diameter

D and length 'l' due to turbulent flow
depends on the velocity V , viscosity µ , density ? , and roughness k. Using Buckingham's
p
-

theorem , obtain an expression for ?p. (16)

16. Using Buckingham's p


theorem, show that the discharge Q consumed by an o
il ring
is given by


Q = Nd3? [µ/?Nd2, s/?N2d3, w/ ?N2d]

Where'd' is the internal diameter of
the ring, N is rotational speed , ? is density , µ is viscosity , s is surface tension and w is
the specific weight of oil. (16)


17. Explain the main parts of a
centrifugal pump with neat sketch. Also discuss about
manometric efficiency, Mechanical efficiency and overall efficiency. (16)



18. Describe the working of Pelton Wheel with neat sketch and state the difference
between impulse and reaction turbine. (16)



19. Describe the working of reciprocating pump with the aid of a sketch. (16)


20. A single acting reciprocating pump, running at 50 rpm delivers 0.01m3/s of water.
The diameter of the piston is 200mm and stroke length 400mm. Determine


(i) The theoretic
al discharge of the pump

(ii) Co
-
efficient of discharge


(iii) Slip and percentage of slip of the pump.