Download 1: Total Question Paper of JNTU-II BTECH-CE-Fluid Mechanics

1: Total Question Paper of JNTU-II BTECH-CE-Fluid Mechanics-Reg-Nov 07-Set
no 1
Code No : R050210104
Set No.1
II B.Tech I Semester Regular Examinations, November 2007
FLUID MECHANICS
(Civil Engineering)
Time: 3 hours
Answer any FIVE Question
All Questions carry equal marks
.......................
Max Marks: 80
1 (a) Define vapour pressure, capillarity, compressibility and surface Tension. Also explain the practical
significance of them.
(b) Derive an expression for the capillary rise of a liquid having surface tension σ and contact angle θ
between two vertical parallel plates a distance ?d? apart. If the plates are of glass, what will be the capillary
rise of water having σ = 0.073 N/m = 00 . Take d = 1mm [8+8]
2. (a) Prove that the total pressure exerted by a static liquid on an inclined plane submerged surface is same
as the force exerted on a vertical plane surface as long as the depth of centre of gravity of the surface is
unaltered.
(b) Determine the horizontal and vertical components of total pressure due to water on a tainted gate shown
in figure 2. Width of gate is 4m. [8+8]
3.(a) What is a flow net. Draw a typical flow net and explain its applications. What are the limitations of
flow nets.
(b) A pipe 50 cm in diameter branches into two pipes of diameters 25 cm and 20 cm respectively as shown
in figure 3. It the average velocity in 50 cm diameter pipe is 4m/sec finds
i. Discharge through 50 cm diameter pipe and
ii. velocity in 20 cm diameter pipe if the average velocity in 25 cm pipe is 3 m/sec
4.(a) State and derive Bernoulli’s theorem, mentioning clearly the assumptions underlying it.
(b) A 45o reducing bend is connected in a pipe line, the diameters at the inlet and outlet of the bend being
40 cm and 20 cm respectively. Find the force exerted by water on the bend if the intensity of pressure at
inlet of bend is 21.58N/cm2. The rate of flow of water is 500 lit/sec. [8+8]
5. (a) Explain the phenomenon of boundary layer separation and its influence on the drag of an immersed
body.
(b) In a flat plate of 2m length and 1m wide, experiments were conducted in a wind tunnel with a wind
speed of 50 KM/hr. The plate is kept at such an angle that the coefficients of drag and lift are 0.18 and 0.9
respectively. Determine drag force, lift force, resultant force and power exerted by the air stream on the
plate. Take density of air as 1.15 KG/m3. [7+9]
6.(a) Draw a neat sketch or Reynolds apparatus and explain how the laminar flow can be demonstrated with
the help of the apparatus.
(b) Two parallel plates kept 100 mm apart have laminar flow of oil between them with a maximum velocity
of 1.5 m/sec. Calculate discharge per meter width, shear stress at the plates and the difference in pressure
between two points 20m apart. Assume viscosity of oil to be 24.5 poise. [8+8]
7. (a) Derive the Darcy – Wasatch equation for friction head loss in a pipe.
(b) Water is flowing through a horizontal pipe line 1500m long and 200 mm in diameter. Pressure at the
two ends of the pipe line are respectively 12 kpa and 2 kpa. If f = 0.015, determine the discharge through
the pipe in liters per minute. Consider only frictional loss. [8+8]
8. (a) Explain the principle and working of picot tube with the help of a neat sketch.
(b) Petroleum oil of (Specific Gravity = 0.93 and viscosity = 13CP) flows is thermally through a horizontal
5cm pipe. A picot tube is inserted at the center of a pipe and its leads are filled with the same oil and
attached to a v-tube containing water. The reading on the manometer is 10 cm. Calculate the volumetric
flow of oil in m3/sec. The coefficient of picot tube is 0.98. [8+8]
....................................
1: Total Question Paper of JNTU-II B.Tech-CE-Fluid Mechanics-Reg-Nov 07-Set
no 2
Code No: R050210104
2
Set No
II B.Tech I Semester Regular Examinations, November 2007
FLUID MECHANICS
(Civil Engineering)
Time: 3 hours
Max Marks:80
Answer any FIVE Questions
All Questions carry equal marks
********
1. (a) Explain the phenomenon of capillarity. Obtain an expression for capillary rise of a liquid.
(b) A pressure gauge is fitted at the bottom of a closed vessel to which a simple manometer is also fitted as
shown in figure Determine the reading indicated by the pressure gauge if manometric liquid is mercury.
(figure 1b) [8+8]
2. (a) What do you mean by Hydrostatic pressure.
(b) Define Total pressure and centre of pressure
(c) A circular plate 2.5m in diameter is submerged in water as shown in figure 2c. Its greatest and least
depths below free surface of water are 3m and 2m respectively. Find
i. Total pressure on front face of the plate and
ii. the position of centre of pressure [3+4+9]
3. (a) Describe briefly different methods of drawing flow nets.
(b) The velocity vector in an incompressible flow is given by V = (6xt + yz2)i + (3t + xy2)j + (xy – 2xyz –
6tz)K
i. Verify whether the continuity equation is satisfied
ii. Determine the acceleration vector at point A (1,1,1) at t = 1.0 [8+8]
4. (a) State and derive Bernoullis theorem, mentioning clearly the assumptions underlying it.
(b) A 450 reducing bend is connected in a pipe line, the diameters at the inlet and outlet of the bend being
40 cm and 20 cm respectively. Find the force exerted by water on the bend if the intensity of pressure at
inlet of bend is 21.58N/cm2. The rate of flow of water is 500 lit/sec. [8+8]
5. (a) Explain how laminar and turbulent boundary layers are formed and distinguish between their
characteristics.
(b) A thin flat plate measuring 75 cm x 25 cm is exposed parallel to a stream of water of uniform velocity
1.2m/sec. The flow takes place parallel to 25 cm side of the plate. If the kinematic viscosity of water is 1.1
centistokes, determine the maximum boundary layer thickness, shearing stress at the trailing edge and the
drage on both sides of the plate. [8+8]
6. (a) Draw a neat sketch of Reynolds apparatus and explain how the laminar flow can be demonstrated
with the help of the apparatus.
(b) Two parallel plates kept 100 mm apart have laminar flow of oil between them with a maximum velocity
of 1.5 m/sec. Calculate discharge per metre width, shear stress at the plates and the difference in pressure
between two points 20m apart. Assume viscosity of oil to be 24.5 poise. [8+8]
7. (a) Derive the Darcy- Weisbach equation for friction head loss in a pipe.
(b) Water is flowing through a horizontal pipe line 1500m long and 200 mm in diameter. Pressure at the
two ends of the pipe line are respectively 12 kpa and 2 kpa. If f = 0.015, determine the discharge through
the pipe in litres per minute. Consider only friction loss. [8+8]
8. (a) Define coefficient of discharge, coefficient of contraction and coefficient of velocity. What is the
relation among them.
(b) Derive the formula for velocity of flow through an orifice.
(c) A 4cm diameter orifice in the vertical side of a tank discharges water. The water surface in the tank is at
a constant level of 2m above the center of the orifice. If the head loss in the orifice is 0.2 m and the
coefficient of contraction can be assumed to be 0.63 estimate
i. the values of the coefficient of velocity and coefficient of discharge
ii. the discharge through orifice and
iii location of point of impact of jet on a horizontal plane located 0.5 m below the center of orifice. [6+4+6]
1: Total Question Paper of JNTU-II BTECH-CE-Fluid Mechanics-Reg-Nov 07-Set
no 3
Code No : R050210104
Set No : 3
II B.Tech I Semester Regular Examinations, November 2007
FLUID MECHANICS
(Civil Engineering )
Time: 3 Hours
Max Marks: 80
Answer any FIVE Questions
All Question carry equal marks
..................
1.(a) Explain the working of a Bourdon pressure gauge with the help of a neat sketch.
(b) An U-tube differential manometer was used to connect two pressure pipes P and Q as shown in figure
the P contains a liquid having specific graity of 1.8 under a pressure of 95kN/m 2. The pipe Q contains
another liquid having specific gratuity of 0.9 under a pressure of 180 KN/m2. Find the difference of
pressure if mercury is used as a U-tube liquid (figure 1b) [8+8]
2.(a) What do you mean by hydrostatic pressure.
(b) Define Total pressure and centre of pressure
(c) A circular plate 2.5 m in diameter is submerged in water as shown in figure 2c. Its greatest and least
depths below free surface of water are 3m and 2m respectively. Find
i. Total pressure on front face of the plate and
ii. the position of centre of pressure [3+4+9]
3.(a) State and explain equation of continuity for incompressible fluid and compressible fluid.
(b) Give examples of stream lien flow, turbulent flow, steady flow, unsteady flow, uniform flow and nonuniform flow.
(c) Oil flows through a pipeline which contracts from 45cm diameter at A to 30 cm diameter at B and then
branches into two pipes C and D. The diameter of the pipe C is 15 cm and iameter of the pipe D is 20cm. If
the velocity at A be 1.8m/sec and that at D be 3.6m/sec Determine (figutre3c)
i. velocity at section B
ii.Discharge at D
iii. Discharge at C
iv.Velocity at C
4. (a) Define potential head, velocity head and datum head.
(b) List out the assumptions and limitations of Bernoulli’s equation.
© 360 liters per second of water is flowing in a pipe. The pipe is bent by 120 0 The diameters at the inlet and
outlet of the bend being 360mm 240 mm respectively and volume of the bend is 0.14m 3. The pressure at
the entrance is 72 KN/m2 and the exit if 2.4m above the entrance section . [3+3+10]
5. (a) Explain the phenomenon of boundary layer separation and its influence on the drag of an immersed
body.
(b) In a flat plate of 2m length and 1m wide, experiments were conducted in a wind tunnel with a wind
speed of 50 Km/hr. the plate is kept at such an angle that the coefficients of drag and lift are 0.18 and 0.9
respectively. Determine drag force, lift force, resultant force and power exerted by the air stream on the
plate. Take density of air as 1.15Kg/m3.
[7+9]
6. (a) Derive the expressions for discharge per unit width and shear stress for flow of viscous fluid between
two parallel plates when one plate is moving and other at rest.
(b) Two parallel plates kept 75 mm apart have laminar flow of glycerin between them with a maximum
velocity of 1m/sec. Calculate the difference in pressure between two points 25m apart and the velocity
gradients at the plates and velocity at 15 mm from the plate. Take viscosity of glycerine as 8.35 poise.
[8+8]
7. (a) Derive and expression for head lost due to sudden contraction of a pipe.
(b) A pipe increases in diameter suddenly from 10 cm to 20 cm. If the discharge of water through the pipe
is 100 lit/sec., determine the loss of head due to sudden enlargement of cross sectional area. Also determine
the difference of pressure between two sections of the pip0e line. [8+8]
8. (a) Define coefficient of discharge, coefficient of contraction and coefficient of velocity. What is the
relation among them.
(b) Derive the formula for velocity of flow through an orifice.
(c) A 4cm diameter orifice in the vertical side of a tank discharges water. The water surface in the tank at a
constant level of 2m above the center of the orifice. If the head loss in the orifice is 0.2 m and the
coefficient of contraction can be assumed to be 0.63 estimate
i. the values of the coefficient of velocity and coefficient of discharge
ii.the discharge through orifice and
iii.location of point of impact of the jet on a horizontal plane located 0.5m below the center of orifice.
[6+4+6]
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