Fourth Semester B.E. Degree Examination, Dec.09/Jan.10Fluid
Mechanics
ME45
Time: 3 hrs. Max. Marks: I00Note: Answer any FIVE full
questions.1 a. Define following terms and mention their SI units.i)
Specific Density ii) Dynamic Viscosity iii) Surface Tension iv)
Specific Gravity
v) Kinematic Viscosity (05 Marks)b. A pipe carries oil of
specific gravity 0.80. A differential manometer connected at two
points'A ' and 'B' of the pipe shows a difference in mercury levels
as 30 em. Find the difference ofpressure head in terms of meters
water. Find also pressure at point A if the pressure at pointB is
1.46 bar. (10 Marks)c. Explain phenomenon of capillarity. Obtain
relation for capillarity rise of liquid. (05 Marks)
2 a. Show that, for a completely submerged plane surface, the
centre of pressure is always belowthe centre of gravity. (10
Marks)b. A piece of metal when submerged in water weighs 667.08
Nand when submerged in liquidof specific gravity 0.8 weighs 686.70
N. Determine the volume of the metallic piece, itsweight in air and
specific gravity of the metal. (10 Marks)
3 a. Explain working ofmicromanometer, with neat sketch. (06
Marks)b. Explain importance ofmetacentric height to determine the
stability of floating bodies.
7/29/2019 2009 -Dec.09- Jan.10-ME45
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ME457 a. For a viscous fluid flow, show that maximum velocity of
flow is twice the average velocity
of flow. (08 Marks)b. Represent Hydraulic gradient line and
total energy line for flow through a pipe with suddenexpansion. (04
Marks). c. Find the rate of flow of water through a pipe of
diameter 20 em and length 50 m, when oneend of the pipe is
connected to a tank and other end of the pipe is open to the
atmosphere.The pipe is horizontal and water level in tank is 4
meters above the axis of pipe. Consideringall the minor losses,
find discharge in Its /sec. Take frictional factor 'f = .009. (08
Marks)
8 a. Define drag force and lift force for objects immersed in
fluid. (04 Marks)b. Explain:i) Boundary Layer Thicknessii)
Displacement Thicknessiii) Momentum Thickness. (06 Marks)c. Explain
for a compressible fluid flow,i) Zone of actionii) Mach angleiii)
Mach cone. (06 Marks)d. A bullet is fired in the air and mach angle
is observed to be 30. Given the temperature of air
is 20C, density 1.2 kg /m3, find velocity of bullet. Assume Y =
1.4 for air, R = 287.4 J/kgK.(04 Marks)
