ii b.tech ii semester, regular examinations, april – 2012...

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Code No: R22014 II B.Tech II Semester, Regular Examinations, April – 2012 HYDRAULICS AND HYDRAULIC MACHINERY (Civil Engineering) Time: 3 hours Max. Marks: 75 Answer any FIVE Questions All Questions carry Equal Marks ~~~~~~~~~~--~~~~~~~~~~ 1. a) What do you understand by i) steady and unsteady flow, ii) uniform and non-uniform flow in the case of channels? b) An irrigation channel of trapezoidal section, having side slope s 3 horizontal to 2 vertical, is to carry a flow of 10 cumec on a longitudinal slope of 1 in 5000. The channel is to be lined for which the value of friction coefficient in Manning’s formula is n = 0.012. Find the dimensions of the most economic section of the channel. (6M+9M) 2. a) A horizontal rectangular channel 4 m wide carries a discharge of 16 m 3 /s. Determine whether a jump may occur at an initial depth of 0.5 m or not. If a jump occurs, determine the sequent depth to this initial depth. Also determine the energy loss in the jump. b) Explain the term hydraulic jump. Derive an expression for the downstream depth of hydraulic jump. (7M+8M) 3. a) Define the term dimensional analysis and model analysis. b) In 1:40 model of a spillway, the velocity and discharge are 2 m/s and 2.5 m 3 /s. Find the corresponding velocity and discharge in the prototype. (7M+8M) 4. a) A jet of water of 10 cm diameter is discharging under a constant head of 80 m. Find the force exerted by the jet on a fixed plate. Take coefficient of velocity as 0.9. b) Show that the force exerted by a jet of water on an inclined fixed plate in the direction of the jet is given by F x = aV 2 Sin 2 , where a= Area of the jet, V= velocity of the jet and =inclination of the plate with the jet. (6M+9M) 5. a) Explain briefly the principles on which a Kaplan turbine works. b) Explain the different types of the efficiency of a turbine (8M+7M) 6. Explain i) Unit speed, ii) Unit discharge, iii) Unit power of a hydraulic turbine. Derive expressions for each of them. (15M) 7. What do you mean by manometric efficiency, mechanical efficiency and overall efficiency of centrifugal pump? (15M) 8. a) Discuss in detail estimation of hydropower potential. b) Explain the terms i) load factor and ii) utilization factor (9M+6M) 1 of 1 R10 SET - 1

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Page 1: II B.Tech II Semester, Regular Examinations, April – 2012 ...indianservers.com/jntukupdates/questionpapers/2-2/REGULAR APRIL... · II B.Tech II Semester, Regular Examinations, April

Code No: R22014

II B.Tech II Semester, Regular Examinations, April – 2012

HYDRAULICS AND HYDRAULIC MACHINERY (Civil Engineering)

Time: 3 hours Max. Marks: 75

Answer any FIVE Questions

All Questions carry Equal Marks

~~~~~~~~~~--~~~~~~~~~~

1. a) What do you understand by i) steady and unsteady flow, ii) uniform and non-uniform flow

in the case of channels?

b) An irrigation channel of trapezoidal section, having side slope s 3 horizontal to 2 vertical, is

to carry a flow of 10 cumec on a longitudinal slope of 1 in 5000. The channel is to be lined for

which the value of friction coefficient in Manning’s formula is n = 0.012. Find the dimensions

of the most economic section of the channel. (6M+9M)

2. a) A horizontal rectangular channel 4 m wide carries a discharge of 16 m3/s. Determine

whether a jump may occur at an initial depth of 0.5 m or not. If a jump occurs, determine the

sequent depth to this initial depth. Also determine the energy loss in the jump.

b) Explain the term hydraulic jump. Derive an expression for the downstream depth of

hydraulic jump. (7M+8M)

3. a) Define the term dimensional analysis and model analysis.

b) In 1:40 model of a spillway, the velocity and discharge are 2 m/s and 2.5 m3/s. Find the

corresponding velocity and discharge in the prototype. (7M+8M)

4. a) A jet of water of 10 cm diameter is discharging under a constant head of 80 m. Find the

force exerted by the jet on a fixed plate. Take coefficient of velocity as 0.9.

b) Show that the force exerted by a jet of water on an inclined fixed plate in the direction of the

jet is given by Fx=� aV2 Sin

2 �, where a= Area of the jet, V= velocity of the jet and

�=inclination of the plate with the jet. (6M+9M)

5. a) Explain briefly the principles on which a Kaplan turbine works.

b) Explain the different types of the efficiency of a turbine (8M+7M)

6. Explain i) Unit speed, ii) Unit discharge, iii) Unit power of a hydraulic turbine. Derive

expressions for each of them. (15M)

7. What do you mean by manometric efficiency, mechanical efficiency and overall efficiency of

centrifugal pump?

(15M)

8. a) Discuss in detail estimation of hydropower potential.

b) Explain the terms i) load factor and ii) utilization factor (9M+6M)

1 of 1

R10 SET - 1

Page 2: II B.Tech II Semester, Regular Examinations, April – 2012 ...indianservers.com/jntukupdates/questionpapers/2-2/REGULAR APRIL... · II B.Tech II Semester, Regular Examinations, April

Code No: R22014

II B.Tech II Semester, Regular Examinations, April – 2012

HYDRAULICS AND HYDRAULIC MACHINERY (Civil Engineering)

Time: 3 hours Max. Marks: 75

Answer any FIVE Questions

All Questions carry Equal Marks

~~~~~~~~~~~~~~~~~~~~~~

1. a) Derive the condition for the best side slope of the most economical trapezoidal channel.

b) Design a concrete lined channel to carry a discharge of 500 cumecs at a slope of 1 in 4000.

The side slopes of the channel may be taken as 1:1. The Manning’s roughness coefficient for

the lining is 0.014. Assume permissible velocity in the section as 2.5 m/s. (8M+7M)

2. a) Show that in a rectangular open channel the critical depth is two thirds of specific energy.

b) A trapezoidal channel having bottom width 8 m and side slope 1:1, carries a discharge of 86

m3/sec. Find the depth conjugate to initial depth of 0.75 m before the jump. Also determine the

energy in the jump. (7M+8M)

3. a) State Buckingham’s �- theorem. Why this theorem is considered superior to Rayleigh’s

method for dimensional analysis?

b) A dam 15 m long is to discharge water at the rate of 120 cumecs under a head of 3 m.

Design the model, if the supply available in the laboratory is 50 l/s. (8M+7M)

4. a) Define the terms: i) Impact of jets, and ii) Jet propulsion.

b) Obtain an expression for the force exerted by a jet of water on a fixed vertical plate in the

direction of the jet. (6M+9M)

5. a) How will you classify the turbines?

b) Differentiate between turbines and pumps. (8M+7M)

6. What do you understand by the characteristics curves of turbine? Name the important

characteristics of a turbine. (15M)

7. Define a centrifugal pump. Explain the working of a single stage centrifugal pump with neat

sketches. (15M)

8. a) Compare and contrast between hydropower station and thermal power station.

b) List out twelve important hydropower plants in India. (9M+6M)

1 of 1

R10 SET - 2

Page 3: II B.Tech II Semester, Regular Examinations, April – 2012 ...indianservers.com/jntukupdates/questionpapers/2-2/REGULAR APRIL... · II B.Tech II Semester, Regular Examinations, April

Code No: R22014

II B.Tech II Semester, Regular Examinations, April – 2012

HYDRAULICS AND HYDRAULIC MACHINERY (Civil Engineering)

Time: 3 hours Max. Marks: 75

Answer any FIVE Questions

All Questions carry Equal Marks

~~~~~~~~~~~~~~~~~~~~~~

1. a) A trapezoidal channel has a bed width of 5 m, side slopes of 1 upon 1.5 and Manning’s n =

0.015. Compute the critical slope and the corresponding discharge for a critical depth of 2 m.

b) Derive the condition for depth of flow of a most economical circular channel section subject

to the condition for maximum velocity. (8M+7M)

2. a) A rectangular channel carries a discharge of 2 m3/sec per meter width. If the loss of energy

in the hydraulic jump is found to be 2.75 m, determine the conjugate depths before and after

the jump.

b) Explain the term hydraulic jump. Derive an expression for the downstream depth of

hydraulic jump. (7M+8M)

3. a) What do you mean by dimensionless numbers? Name any three dimensionless numbers

b) A 1:50 spillway model has a discharge of 1.5 cumecs. What is the corresponding prototype

discharge? If a flood phenomenon takes 6 h to occur in the prototype, how long should it take

in the model. (8M+7M)

4. a) Obtain an expression for the force exerted by a jet of water on a fixed vertical plate in the

direction of the jet

b) A jet of velocity of 20 m/s strikes a flat plate inclined at 30° with the axis of the jet. If the

cross sectional area of the jet is 20 cm2, find the force exerted by the jet on the plate. Also

calculate the components of the force in the direction normal to the jet. Find also the ratio in

which the discharge gets divided after striking the plate. (9M+6M)

5. a) A pelton wheel, working under a head of 400 m, produces 12000kW at 400 rpm. If the

efficiency of the wheel is 80%, determine i) discharge of the turbine, ii) diameter of the wheel

and iii) diameter of the nozzle (assume suitable data)

b) With a neat sketch discuss layout of a typical hydropower installation. (7M+8M)

6. a) How does the load variation on generator have effect on turbine in hydropower installation?

What is the role of a governor?

b) What are unit quantities? Define the unit quantities for turbine (8M+7M)

7. a) Discuss in general the main operating characteristics of a centrifugal pump. What is the

importance of constant efficiency curves?

b) Define cavitation. What are the effects of cavitation? (8M+7M)

8. a) Discuss in detail estimation of hydropower potential.

b) Explain the terms i) load factor and ii) utilization factor (9M+6M)

1 of 1

R10 SET - 3

Page 4: II B.Tech II Semester, Regular Examinations, April – 2012 ...indianservers.com/jntukupdates/questionpapers/2-2/REGULAR APRIL... · II B.Tech II Semester, Regular Examinations, April

Code No: R22014

II B.Tech II Semester, Regular Examinations, April – 2012

HYDRAULICS AND HYDRAULIC MACHINERY (Civil Engineering)

Time: 3 hours Max. Marks: 75

Answer any FIVE Questions

All Questions carry Equal Marks

~~~~~~~~~~~~~~~~~~~~~~

1. a) A trapezoidal channel has a bottom width of 6 m and side slopes of 1:1. If the depth of flow

is 1.5 m at a discharge of 20 m3/sec, compute the specific energy and the critical depth.

b) Explain the terms specific energy of a flowing liquid, minimum specific energy, critical

depth, critical velocity and alternate depths as applied to non-uniform flow. (8M+7M)

2. State and discuss the assumption made in the derivation of the dynamic equation for gradually

varied flow. Starting from first principles derive equations for the slope of the water surface in

gradually varied flow with respect to i) channel bed, ii) horizontal. (15M)

3. a) What do you mean by fundamental units and derived units? Give examples.

b) An aeroplane model of scale ratio 1:30 is tested in water, which is 50 times more viscous

and 800 times more dense than the air. If the pressure drop in the model during test is 225.63

N/m2, find the corresponding pressure drop in the prototype. (7M+8M)

4. a) Derive an expression for the force, work done, and efficiency of a moving curved vane.

b) A jet of water diameter 0.12 m moving with a velocity of 30 m/s strikes a curved fixed

symmetrical plate at the center. Find the force exerted by the jet of water in the direction of the

jet, if the jet is deflected through an angle of 120° at the outlet of the curved plate. (9M+6M)

5. a) A Pelton wheel turbine produces 20 MW while running at 700 rpm under an effective head

of 1700 m. Calculate, i) least diameter of the jet, ii) mean diameter of the runner and

iii) Number of buckets

b) Explain the different types of the efficiency of a turbine (8M+7M)

6. a) What is cavitation? How can it be avoided in reaction turbine?

b) What is the basis of selection of a turbine at a particular place? (7M+8M)

7. a) Explain condition in which two pumps may be operated in series or in parallel.

b) What is multistage pump and what are its advantages (8M+7M)

8. a) What is mass curve? Explain the procedure for preparing a mass curve and also its uses.

b) What area the essential stream flow data for water power studies. (8M+7M)

1 of 1

R10 SET - 4