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APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
THIRD SEMESTER B.TECH DEGREE EXAMINATION, DECEMBER 2017
Course Code: CH205
Course Name: FLUID AND PARTICLE MECHANICS-I
Max. Marks: 100 Duration: 3 Hours
PART A
Answer any two full questions, each carries 15 marks. Marks
1 One of the important characteristic of fluid is "Weakness of the potential energy
associated with the intermolecular forces relative to the kinetic energy associated
with the vibrations of the individual molecules; the molecules are too busy
vibrating to hang onto one another and thus do not form a long-lived crystal".
Explain.

Find the density in slugs/ft3 of air at sea level with 25 oC temperature and 1 atm
pressure. Calculate pressure and density at 1500 m altitude assuming atmosphere
follows adiabatic and reversible process. Take Cp/Cv as 1.4 for air.

2 Find the apparent viscosity of fluid at 2000 N/m2 from the data. Predict the type of
the fluid.
Stress, N/m2 100 200 500 1000 2000 5000
Strain Rate, 1/s 55 75 110 150 200 300

A tubular centrifuge is used to separate chlorobenzene with a density of 1090
kg/m3 from an aqueous wash liquor having density 1010 kg/m3. The centrifuge
has an inside diameter of 200 mm and rotates at 10000 rpm. The free liquid
surface inside the bowl is 60 mm from the axis of rotation. If the centrifugal bowl
is to contain equal masses of two liquids, what should be the radial distance from
the axis to the top of the overflow of the heavy liquid?

3 Explain phenomenological laws. Explain the phenomenological law in fluid flow.
One cubic foot of water weighs 62.4 lbf under conditions of standard gravity.
What is its weight? What is its density? What is its weight on the moon 5.4
What is its density on the moon? Find all values in SI units.

Discuss the significance of metacentre and metacentric height.
The pressure between two points A and B in a pipe conveying oil of specific
gravity 0.8 is measured by an inverted U-tube. The column connected to point b
stands 1.6 m higher than that at point A. A commercial pressure gauge attached
directly to the pipe at A reads 1.125 kg(f)/cm2. Determine its reading when
attached directly to the pipe at B.

PART B
Answer any two full questions, each carries 15 marks.
4 Water is draining from an open conical funnel at the same rate at which it is
entering at the top. The diameter of the funnel is 1 cm at the top and 0.5 cm at the
bottom, and it is 5 cm high. The mass flow rate of water is 60kg/h. Determine the

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volumetric flow rate of the water and the value of the Reynolds number entering
and leaving the funnel?
Stating different assumption, derive Bernoulli equation. State different correction
factor included to modify Bernoulli equation.

5 The water flows through a 2.5 in inside diameter pipe at velocity of 0.06 m/s and
30 oC at known pressure. Calculate the Reynolds number in the pipe. If the above
pipe diverges and then flow through 6 in inside diameter pipe, what will be the
Reynolds number in 5 in pipe? Predict whether the flow is laminar or turbulent.

Explain the concept of boundary-layer formation over a flat plate.
Water flows from a tap at a pressure of 250 kN/m2 above atmospheric. What is the
velocity of the jet if frictional effects are neglected?

6 Explain the different type of flow based on water flow in a river.
Explain Eulerain and Lagrangian approaches.
A stream function in a two dimensional flow is 2xy. Show that the flow is
irrotational and determine corresponding velocity potential

PART C
Answer any two full questions, each carries 20 marks.
7 Water is flowing at Reynolds number 2000 through pipe of 10 cm inside diameter
and 10 m length. Then the water flows through another pipe of 20 cm inside
diameter and 10 m length after an expansion joint. Find the total pressure drop in
the system.

Draw a neat sketch of globe valve. Explain the cavitation phenomenon in globe
valve.

Compare between elbows and bends
8 Calculate the frictional pressure drop for a commercial steel pipe with the
following characteristics: length L 30.48 inside diameter d 0.0526 pipe
roughness 0.000045 steady liquid flow rate 9.085 liquid dynamic
viscosity 0.01 Pa liquid density 1200 kg/m3. Use Blasius equation for
calculating friction factor.

Draw a neat sketch of rotameter.
Explain the different type of joints. Draw neat sketch of each joints.
9 What are the relation between Churchill friction factor, Fanning friction factor and
Darcy friction factor?

Explain equivalent diameter for non-circular pipes and equivalent length for
piping elements.

Draw friction factor chart and explain the effect of Reynolds number on friction
factor.

Derive the expression for volumetric flow rate of a fluid in an orifice meter with
known dimensions if a manometer is connected to measure the pressure drop.