Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer of the following (Any seven questions
only):
Where is a water hammer developed?
The force of impingement of a jet on a vane increases, if
The fluid coming into the centrifugal pump is accelerated by
The overall efficiency of a reaction turbine is the ratio of
A jet of water issues from a nozzle with a velocity of $ 20~m/s $ and it impinges normally on a flat plate moving away from it at $ 10~m/s $. If the cross-sectional area of the jet is $ 0.02~m^2 $ and the density of water is taken as $ 1000~kg/m^3 $, then the force developed on the plate will be
Which of the following turbine has least efficiency
The unit speed $ N_u $ of a turbine having a rotational speed of $ N $ and head $ H $ is equal to
What does Euler's equation of turbo machines relate to?
Without residual whirl in the flow at the entrance to a draft tube, the best cone angle is
A centrifugal pump is started with its delivery valve kept
Q.2 Solve both questions :
Show that the force exerted by a jet of water on moving inclined plane in the direction of jet is
given by $ F_x = \rho a (V - u)^2 \sin^2 \theta $
Where, $ a = $ area of jet,
$
\theta = $ inclination of the plate with the jet and $ V = $ velocity of jet
Show the general layout of a hydro-electric power plant and explain each component in brief.
Q.3 Solve both questions :
What is a hydraulic turbine? How are they classified? With the help of neat sketch, explain the construction and working of a Pelton wheel turbine.
An inward flow reaction turbine has external and internal diameters as 1 m and 0.5 m respectively. The turbine is running at 200 r.p.m. and width of turbine at inlet is 200 mm. The velocity of flow through the runner is constant and is equal to $ 1.8~m/s $. The guide blades make an angle of $ 10^{\circ} $ to the tangent of the wheel and the discharge at the outlet of the turbine is radial. Calculate all velocity vectors and draw the inlet and outlet velocity triangles. Also calculate mass flow through the runner/second, power developed and hydraulic efficiency.
Q.4 Solve both questions :
Draw a schematic of a Francis turbine and explain briefly its construction and working.
A turbine is to operate under a head of 28 m at 200 r.p.m. The discharge and overall efficiency of the turbine are $ 8.5~m^3/s $ and 89%, respectively. Determine (i) specific speed of the turbine, (ii) power generated and (iii) types of turbine.
Q.5 Solve both questions :
Explain different component parts of a centrifugal pump.
A centrifugal pump delivers water at the rate of 40 litres / sec for a total head of 30 m. Find the output of the pump. If the overall efficiency of the set consisting of the pump and the electric motor is 75%, find the power required to drive the motor.
Q.6 Solve both questions :
What is model analysis? What are the advantages and applications of model testing?
A 1:8 model of 12 ft diameter turbine is operated at 600 r.p.m. under a net head of 54.0 ft. Under this mode of operation, the bhp and Q of the model were observed, to be 332 hp and 62 cfs, respectively. From the above data compute (i) the specific speed of the model and the value of $ \sigma $ (ii) the efficiency and shaft torque of the model, (iii) the efficiency of the prototype, (iv) the flow rate and horsepower of the prototype if it is operated at 450 r.p.m. under a net head of 200 ft.
Q.7 Solve both questions :
What are the causes of cavitation? How will you prevent the cavitation in hydraulic Machines?
Define Indicator diagram. How will you prove that area of indicator diagram is proportional to the work done by the reciprocating pump?
Q.8 Write short notes on the following:
Governing of water turbine
Draft Tube.
Q.9 Write short notes on any two of the following:
Turbine
Specific speed of pump
Priming of pump
Slip in reciprocating pump
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer of the following (Any seven questions
only):
Where is a water hammer developed?
The force of impingement of a jet on a vane increases, if
The fluid coming into the centrifugal pump is accelerated by
The overall efficiency of a reaction turbine is the ratio of
A jet of water issues from a nozzle with a velocity of $ 20~m/s $ and it impinges normally on a flat plate moving away from it at $ 10~m/s $. If the cross-sectional area of the jet is $ 0.02~m^2 $ and the density of water is taken as $ 1000~kg/m^3 $, then the force developed on the plate will be
Which of the following turbine has least efficiency
The unit speed $ N_u $ of a turbine having a rotational speed of $ N $ and head $ H $ is equal to
What does Euler's equation of turbo machines relate to?
Without residual whirl in the flow at the entrance to a draft tube, the best cone angle is
A centrifugal pump is started with its delivery valve kept
Q.2 Solve both questions :
Show that the force exerted by a jet of water on moving inclined plane in the direction of jet is
given by $ F_x = \rho a (V - u)^2 \sin^2 \theta $
Where, $ a = $ area of jet,
$
\theta = $ inclination of the plate with the jet and $ V = $ velocity of jet
Show the general layout of a hydro-electric power plant and explain each component in brief.
Q.3 Solve both questions :
What is a hydraulic turbine? How are they classified? With the help of neat sketch, explain the construction and working of a Pelton wheel turbine.
An inward flow reaction turbine has external and internal diameters as 1 m and 0.5 m respectively. The turbine is running at 200 r.p.m. and width of turbine at inlet is 200 mm. The velocity of flow through the runner is constant and is equal to $ 1.8~m/s $. The guide blades make an angle of $ 10^{\circ} $ to the tangent of the wheel and the discharge at the outlet of the turbine is radial. Calculate all velocity vectors and draw the inlet and outlet velocity triangles. Also calculate mass flow through the runner/second, power developed and hydraulic efficiency.
Q.4 Solve both questions :
Draw a schematic of a Francis turbine and explain briefly its construction and working.
A turbine is to operate under a head of 28 m at 200 r.p.m. The discharge and overall efficiency of the turbine are $ 8.5~m^3/s $ and 89%, respectively. Determine (i) specific speed of the turbine, (ii) power generated and (iii) types of turbine.
Q.5 Solve both questions :
Explain different component parts of a centrifugal pump.
A centrifugal pump delivers water at the rate of 40 litres / sec for a total head of 30 m. Find the output of the pump. If the overall efficiency of the set consisting of the pump and the electric motor is 75%, find the power required to drive the motor.
Q.6 Solve both questions :
What is model analysis? What are the advantages and applications of model testing?
A 1:8 model of 12 ft diameter turbine is operated at 600 r.p.m. under a net head of 54.0 ft. Under this mode of operation, the bhp and Q of the model were observed, to be 332 hp and 62 cfs, respectively. From the above data compute (i) the specific speed of the model and the value of $ \sigma $ (ii) the efficiency and shaft torque of the model, (iii) the efficiency of the prototype, (iv) the flow rate and horsepower of the prototype if it is operated at 450 r.p.m. under a net head of 200 ft.
Q.7 Solve both questions :
What are the causes of cavitation? How will you prevent the cavitation in hydraulic Machines?
Define Indicator diagram. How will you prove that area of indicator diagram is proportional to the work done by the reciprocating pump?
Q.8 Write short notes on the following:
Governing of water turbine
Draft Tube.
Q.9 Write short notes on any two of the following:
Turbine
Specific speed of pump
Priming of pump
Slip in reciprocating pump
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Questions
Choose the correct answer (any seven) :
Buckets and blades used in a turbine are used to
_______ is the electric power obtained from the energy of the water.
In reaction turbine hydraulic efficiency is
In what type of turbine water enters in radial direction and leaves axial direction?
Head under which Kaplan turbine is operated is
The difference between gross head and friction losses is
Pipes of largest diameter which carry water from reservoir to the turbines is known as
Different velocities in a centrifugal pump are determined by using
A multistage centrifugal pump has more than two
If we raise the liquid level in the suction vessel, cavitation
Answer the following:
A jet of water from a nozzle is deflected through from its original direction by curved plate which it enters tangentially without shock with a velocity of and leaves with a mean velocity of . If the discharge from the nozzle is , calculate the magnitude and direction of the resultant force on the vane, if the vane is stationary.
A jet strikes tangentially a smooth curved vane moving in the same direction as the jet, and the jet gets reversed in the direction. Show that the maximum efficiency is slightly less than percent.
Answer the following:
Define the degree of reaction. Find out the value of degree of reaction ($R$) for Pelton turbine and Reaction turbine.
A single jet Pelton wheel runs at under a head of . The jet diameter is , its deflection inside the bucket is and its relative velocity is reduced by due to friction. Determine— (i) water power; (ii) resultant force on the bucket; (iii) overall efficiency. Take : Mechanical losses = , coefficient of velocity = , and speed ratio = .
Answer the following:
What do you mean by hydraulic turbine? Give the comparison between impulse and reaction turbines.
An inward flow reaction turbine has external and internal diameters as and . The turbine is running at The width of the turbine at inlet is and velocity of flow through the runner is constant and is equal to . The guide blades make an angle of to the tangent of the wheel and discharge at the outlet of the turbine is radial. Draw the inlet and outlet velocity triangles and determine— (i) the absolute velocity of water at inlet of the runner; (ii) the velocity of whirl at inlet; (iii) the relative velocity at inlet; (iv) the runner blade angles; (v) width of runner at outlet; (vi) weight of water flowing through the runner per second; (vii) head at inlet of the turbine; (viii) power developed; (ix) hydraulic efficiency of the turbine.
Answer the following:
What is a draft tube? Can we use draft tube in an impulse turbine? Describe different types of draft tubes with neat sketches.
State the advantages and disadvantages of a Francis turbine over a Pelton wheel.
Explain with neat sketch the working of a Kaplan turbine. What is the difference between a propeller turbine and a Kaplan turbine?
Answer the following:
What is cavitation? Enumerate some methods to avoid cavitation in water turbines.
A Francis turbine is to operate under a head of . If it generates power and the overall efficiency turbine is , determine speed ($N$) and discharge of the turbine.
Answer the following:
Explain briefly, with neat sketches, the following types of casings in centrifugal pumps: (i) Volute casing (ii) Vortex casing
The impeller of a centrifugal pump having external and internal diameters and respectively, width at outlet and running at works against a head of . The velocity of flow through the impeller is constant and equal to . The vanes are set back at an angle of at outlet. Determine (i) inlet vane angle, (ii) work done by the impeller on water per second and (iii) manometric efficiency.
Answer the following:
It is required to pump water out of deep well under a total head of . A number of identical pumps of design speed and specific speed with a rated capacity of are available. How many pumps are required and how should they be connected whether in series or in parallel?
Two geometrically similar pumps are running at the same speed of One pump has an impeller diameter of and lifts water at the rate of against a head of . Determine the head and impeller diameter of the other pump to deliver half the discharge.
Answer the following:
What is priming? Why is it necessary?
Describe the principle and working of a reciprocating pump. How are they classified?
Define slip, percentage slip and negative slip of a reciprocating pump.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer (any seven):
Reciprocating pump is a/an
How many numbers of valves are required for the rotary pump?
When the casing in a centrifugal pump decelerates the flow, what increases?
The fundamental significance of all the turbo-machinery is
Kaplan turbine is a/an
The function of the draft tube is
In which turbine, the pressure energy of water is first converted into kinetic energy by means of nozzle kept close to the runner?
If the blades of the axial flow turbine are fixed, these are called
Which compressors are suitable for large volume flow rates of above $ 1200~m^3/min $?
Which among the following is the formula for force when it strikes the plate?
Q.2 Solve both questions :
Show that the force exerted by a jet of water on an inclined fixed plane in the direction of jet
is
given by $ F_x = \rho a V^2 \sin^2 \theta $
where, $ a = $ area of the jet, $
\theta
= $ inclination of the plate with the jet and $ V = $ velocity of the jet.
A jet of water of diameter 50 mm moving with a velocity of $ 25~m/s $ impinges on a fixed curved plate tangentially at one end at an angle of $ 30^{\circ} $ to the horizontal. Calculate the resultant force of the jet on the plate if the jet is deflected through an angle of $ 50^{\circ} $. Take $ g = 10~m/s^2 $.
Q.3 Solve both questions :
Find an expression for the propelling force and the work done per second on a tank which is provided with an orifice through which jet of water is coming out and tank is free to move.
Define the degree of reaction. Find out the value of degree of reaction (R) for Pelton turbine and actual reaction turbine.
Q.4 Solve both questions :
How will you classify the turbines?
A reaction turbine works at 450 r.p.m. under a head of 120 meters. Its diameter at inlet is 120 cm and the flow area is $ 0.4~m^2 $. The angles made by absolute and relative velocities at inlet are $ 20^{\circ} $ and $ 60^{\circ} $ respectively with the tangential velocity. Determine (i) volume flow rate, (ii) power developed and (iii) hydraulic efficiency.
Q.5 Solve both questions :
What is a draft tube? Why is it used in a reaction turbine? Describe different types of draft tubes with neat sketches.
A turbine is to operate under a head of 25 m at 200 r.p.m. The discharge and overall efficiencies of the turbine are $ 9~m^3/s $ and 90% simultaneously. Determine (i) specific speed of the turbine, (ii) power generated and (iii) type of turbine.
Q.6 Solve both questions :
Differentiate between (i) Kaplan and Propeller turbines and (ii) Centrifugal and Reciprocating pumps.
The cylinder bore diameter of a single-acting reciprocating pump is 150 mm and its stroke is 300 mm. The pump runs at 50 r.p.m. and lifts water through a height of 25 m. The delivery pipe is 22 m long and 100 mm in diameter. Find the theoretical discharge and the theoretical power required to run the pump. If the actual discharge is 4.2 litres/s, find the percentage slip. Also, determine the acceleration head at the beginning and middle of the delivery stroke.
Q.7 Solve all three questions :
What is priming? Why is it necessary?
Draw and discuss the operating characteristic curves of a centrifugal pump.
A centrifugal pump is to discharge $ 0.118~m^3/s $ at a speed of 1450 r.p.m. against a head of 25 m. The impeller diameter is 250 mm, its width at outlet is 50 mm and manometric efficiency is 75%. Determine the vane angle at the outer periphery of the impeller.
Q.8 Solve both questions :
Find the number of pumps required to take water from a deep well under a total head of 89 m. All the pumps are identical and are running at 800 r.p.m. The specific speed of each pump is given as 25 while the rated capacity of each pump is $ 0.16~m^3/s $.
Describe with a neat sketch the construction and working of single-stage single-acting reciprocating air compressor. Also explain its actual P-V diagram.
Q.9 Solve both questions :
What do you mean by multistage compression? State its advantages.
Determine the impeller diameters and the width at the impeller exit and the power required to
drive
the compressor from the following data:
Speed (N) = 12500 rev/min
Mass flow rate (m) = 15 kg/s
Pressure ratio = 4:1
Isentropic efficiency = 75%
Slip factor = 0.9
Flow coefficient at impeller exit = 0.3
Hub diameter of the eye = 15 cm
Axial velocity of air at entry to and exit from the impeller = 150 m/s
Stagnation temperature at inlet = 295 K
Stagnation pressure at inlet = 1.0 bar
Assume equal pressure ratio in the impeller and diffuser.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer (any seven):
Reciprocating pump is a/an
How many numbers of valves are required for the rotary pump?
When the casing in a centrifugal pump decelerates the flow, what increases?
The fundamental significance of all the turbo-machinery is
Kaplan turbine is a/an
The function of the draft tube is
In which turbine, the pressure energy of water is first converted into kinetic energy by means of nozzle kept close to the runner?
If the blades of the axial flow turbine are fixed, these are called
Which compressors are suitable for large volume flow rates of above $ 1200~m^3/min $?
Which among the following is the formula for force when it strikes the plate?
Q.2 Solve both questions :
Show that the force exerted by a jet of water on an inclined fixed plane in the direction of jet
is
given by $ F_x = \rho a V^2 \sin^2 \theta $
where, $ a = $ area of the jet, $
\theta
= $ inclination of the plate with the jet and $ V = $ velocity of the jet.
A jet of water of diameter 50 mm moving with a velocity of $ 25~m/s $ impinges on a fixed curved plate tangentially at one end at an angle of $ 30^{\circ} $ to the horizontal. Calculate the resultant force of the jet on the plate if the jet is deflected through an angle of $ 50^{\circ} $. Take $ g = 10~m/s^2 $.
Q.3 Solve both questions :
Find an expression for the propelling force and the work done per second on a tank which is provided with an orifice through which jet of water is coming out and tank is free to move.
Define the degree of reaction. Find out the value of degree of reaction (R) for Pelton turbine and actual reaction turbine.
Q.4 Solve both questions :
How will you classify the turbines?
A reaction turbine works at 450 r.p.m. under a head of 120 meters. Its diameter at inlet is 120 cm and the flow area is $ 0.4~m^2 $. The angles made by absolute and relative velocities at inlet are $ 20^{\circ} $ and $ 60^{\circ} $ respectively with the tangential velocity. Determine (i) volume flow rate, (ii) power developed and (iii) hydraulic efficiency.
Q.5 Solve both questions :
What is a draft tube? Why is it used in a reaction turbine? Describe different types of draft tubes with neat sketches.
A turbine is to operate under a head of 25 m at 200 r.p.m. The discharge and overall efficiencies of the turbine are $ 9~m^3/s $ and 90% simultaneously. Determine (i) specific speed of the turbine, (ii) power generated and (iii) type of turbine.
Q.6 Solve both questions :
Differentiate between (i) Kaplan and Propeller turbines and (ii) Centrifugal and Reciprocating pumps.
The cylinder bore diameter of a single-acting reciprocating pump is 150 mm and its stroke is 300 mm. The pump runs at 50 r.p.m. and lifts water through a height of 25 m. The delivery pipe is 22 m long and 100 mm in diameter. Find the theoretical discharge and the theoretical power required to run the pump. If the actual discharge is 4.2 litres/s, find the percentage slip. Also, determine the acceleration head at the beginning and middle of the delivery stroke.
Q.7 Solve all three questions :
What is priming? Why is it necessary?
Draw and discuss the operating characteristic curves of a centrifugal pump.
A centrifugal pump is to discharge $ 0.118~m^3/s $ at a speed of 1450 r.p.m. against a head of 25 m. The impeller diameter is 250 mm, its width at outlet is 50 mm and manometric efficiency is 75%. Determine the vane angle at the outer periphery of the impeller.
Q.8 Solve both questions :
Find the number of pumps required to take water from a deep well under a total head of 89 m. All the pumps are identical and are running at 800 r.p.m. The specific speed of each pump is given as 25 while the rated capacity of each pump is $ 0.16~m^3/s $.
Describe with a neat sketch the construction and working of single-stage single-acting reciprocating air compressor. Also explain its actual P-V diagram.
Q.9 Solve both questions :
What do you mean by multistage compression? State its advantages.
Determine the impeller diameters and the width at the impeller exit and the power required to
drive
the compressor from the following data:
Speed (N) = 12500 rev/min
Mass flow rate (m) = 15 kg/s
Pressure ratio = 4:1
Isentropic efficiency = 75%
Slip factor = 0.9
Flow coefficient at impeller exit = 0.3
Hub diameter of the eye = 15 cm
Axial velocity of air at entry to and exit from the impeller = 150 m/s
Stagnation temperature at inlet = 295 K
Stagnation pressure at inlet = 1.0 bar
Assume equal pressure ratio in the impeller and diffuser.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct option of the following (any seven):
In hydraulic turbines,
Which principle is used in hydraulic turbines?
Which among the following is not a unit quantity of turbine?
The overall efficiency of a reaction turbine is the ratio of
How many valves are there in rotary pump?
The ratio of power at the shaft of turbine and power delivered by water to runner is known as
Which of the following turbines has least efficiency?
The hydraulic efficiency of Pelton turbine will be maximum when the blade velocity is equal to
When the casing in a centrifugal pump decelerates the flow, what does increase?
Centrifugal pump works by imparting
Q.2 Solve both questions :
A jet of water strikes with a velocity of $ 35~m/s $ a flat plate inclined at $ 30^{\circ} $ with the axis of the jet. If the cross-sectional area of the jet is $ 25~cm^2 $, determine- (i) the force exerted by the jet on the plate; (ii) the components of the force in the direction normal to the jet; (iii) the ratio in which the discharge gets divided after striking the plate.
A jet of water of diameter 60 mm moving with a velocity of $ 40~m/s $, strikes a curved fixed plate tangentially at one end at an angle of $ 30^{\circ} $ to horizontal. The jet leaves the plate at an angle of $ 20^{\circ} $ to the horizontal. Find the force exerted by the jet on the plate in the horizontal and vertical directions.
Q.3 Solve both questions :
A Pelton wheel, having a mean bucket diameter of 1.2 m, is running at 1000 r.p.m. The net head on the Pelton wheel is 840 m. If the side clearance angle is $ 15^{\circ} $ and discharge through the nozzle is $ 0.12~m^3/s $ determine (i) power available at the nozzle, and (ii) hydraulic efficiency of the turbine.
Describe, with the help of sketches, the working of an impulse turbine.
Q.4 Solve both questions :
What is a hydraulic turbine? How will you classify them?
In an inward flow reaction turbine, the head on the turbine is 32 m. The external and internal diameters are 1.43 m and 0.71 m respectively. The velocity of flow through the runner is constant and equal to $ 3.2~m/s $. The guide blade angle is $ 10^{\circ} $ and the runner vanes are rigid at inlet. If the discharge at outlet is radial, determine (i) the speed of the turbine, (ii) the vane angle at outlet of the runner and (iii) hydraulic efficiency.
Q.5 Solve both questions :
Draw a schematic of a Francis turbine and explain briefly its construction and working.
A turbine is to operate under a head of 28 m at 200 r.p.m. The discharge and overall efficiency of the turbine are $ 8.5~m^3/s $ and 89%, simultaneously. Determine (i) specific speed of the turbine, (ii) power generated and (iii) types of turbine.
Q.6 Solve both questions :
What is cavitation? How can it be avoided in reaction turbines?
A turbine is to operate under a head of 23 m at 180 r.p.m. The discharge is $ 9~m^3/s $. If the overall efficiency is 90 percent, determine (i) power generated, (ii) specific speed of the turbine and (iii) types of turbine.
Q.7 Solve both questions :
List the main component parts of a centrifugal pump and explain them briefly.
The impeller of a centrifugal pump has an external diameter of 500 mm and internal diameter of 220 mm and it runs at 1400 r.p.m. Assuming a constant radial flow through the impeller at $ 2.4~m/s $ and that the vanes at exit are set back at an angle of $ 22^{\circ} $, determine- (i) the inlet vane angle; (ii) the angle, absolute velocity of water at exit makes with the tangent; (iii) the work done per N of water.
Q.8 Solve both questions :
A centrifugal pump impeller has diameters at inlet and outlet as 350 mm and 720 mm respectively. The flow velocity at outlet is $ 2.5~m/s $ and the vanes are set back at an angle of $ 45^{\circ} $ at the outlet. If the manometric efficiency is 70%, calculate the minimum starting speed of the pump.
In order to predict the performance of a large centrifugal pump, a scale model of one-sixth size was made with the following specifications: Power $ P = 25~kW $, Head $ H_{mano} = 7~m $, Speed $ N = 1000~r.p.m $. If the prototype pump has to work against a head of 22 m, calculate its (i) working speed, (ii) the power required to drive it and (iii) the ratio of the flow rates handled by the two pumps.
Q.9 Solve both questions :
What is a reciprocating pump? Describe the principle and working of a reciprocating pump with a neat sketch. Why is a reciprocating pump not coupled directly to the motor? Discuss the reason in detail.
What is negative slip in reciprocating pump? Explain with neat sketches the function of air vessels in a reciprocating pump.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct option of the following (any seven):
In hydraulic turbines,
Which principle is used in hydraulic turbines?
Which among the following is not a unit quantity of turbine?
The overall efficiency of a reaction turbine is the ratio of
How many valves are there in rotary pump?
The ratio of power at the shaft of turbine and power delivered by water to runner is known as
Which of the following turbines has least efficiency?
The hydraulic efficiency of Pelton turbine will be maximum when the blade velocity is equal to
When the casing in a centrifugal pump decelerates the flow, what does increase?
Centrifugal pump works by imparting
Q.2 Solve both questions :
A jet of water strikes with a velocity of $ 35~m/s $ a flat plate inclined at $ 30^{\circ} $ with the axis of the jet. If the cross-sectional area of the jet is $ 25~cm^2 $, determine- (i) the force exerted by the jet on the plate; (ii) the components of the force in the direction normal to the jet; (iii) the ratio in which the discharge gets divided after striking the plate.
A jet of water of diameter 60 mm moving with a velocity of $ 40~m/s $, strikes a curved fixed plate tangentially at one end at an angle of $ 30^{\circ} $ to horizontal. The jet leaves the plate at an angle of $ 20^{\circ} $ to the horizontal. Find the force exerted by the jet on the plate in the horizontal and vertical directions.
Q.3 Solve both questions :
A Pelton wheel, having a mean bucket diameter of 1.2 m, is running at 1000 r.p.m. The net head on the Pelton wheel is 840 m. If the side clearance angle is $ 15^{\circ} $ and discharge through the nozzle is $ 0.12~m^3/s $ determine (i) power available at the nozzle, and (ii) hydraulic efficiency of the turbine.
Describe, with the help of sketches, the working of an impulse turbine.
Q.4 Solve both questions :
What is a hydraulic turbine? How will you classify them?
In an inward flow reaction turbine, the head on the turbine is 32 m. The external and internal diameters are 1.43 m and 0.71 m respectively. The velocity of flow through the runner is constant and equal to $ 3.2~m/s $. The guide blade angle is $ 10^{\circ} $ and the runner vanes are rigid at inlet. If the discharge at outlet is radial, determine (i) the speed of the turbine, (ii) the vane angle at outlet of the runner and (iii) hydraulic efficiency.
Q.5 Solve both questions :
Draw a schematic of a Francis turbine and explain briefly its construction and working.
A turbine is to operate under a head of 28 m at 200 r.p.m. The discharge and overall efficiency of the turbine are $ 8.5~m^3/s $ and 89%, simultaneously. Determine (i) specific speed of the turbine, (ii) power generated and (iii) types of turbine.
Q.6 Solve both questions :
What is cavitation? How can it be avoided in reaction turbines?
A turbine is to operate under a head of 23 m at 180 r.p.m. The discharge is $ 9~m^3/s $. If the overall efficiency is 90 percent, determine (i) power generated, (ii) specific speed of the turbine and (iii) types of turbine.
Q.7 Solve both questions :
List the main component parts of a centrifugal pump and explain them briefly.
The impeller of a centrifugal pump has an external diameter of 500 mm and internal diameter of 220 mm and it runs at 1400 r.p.m. Assuming a constant radial flow through the impeller at $ 2.4~m/s $ and that the vanes at exit are set back at an angle of $ 22^{\circ} $, determine- (i) the inlet vane angle; (ii) the angle, absolute velocity of water at exit makes with the tangent; (iii) the work done per N of water.
Q.8 Solve both questions :
A centrifugal pump impeller has diameters at inlet and outlet as 350 mm and 720 mm respectively. The flow velocity at outlet is $ 2.5~m/s $ and the vanes are set back at an angle of $ 45^{\circ} $ at the outlet. If the manometric efficiency is 70%, calculate the minimum starting speed of the pump.
In order to predict the performance of a large centrifugal pump, a scale model of one-sixth size was made with the following specifications: Power $ P = 25~kW $, Head $ H_{mano} = 7~m $, Speed $ N = 1000~r.p.m $. If the prototype pump has to work against a head of 22 m, calculate its (i) working speed, (ii) the power required to drive it and (iii) the ratio of the flow rates handled by the two pumps.
Q.9 Solve both questions :
What is a reciprocating pump? Describe the principle and working of a reciprocating pump with a neat sketch. Why is a reciprocating pump not coupled directly to the motor? Discuss the reason in detail.
What is negative slip in reciprocating pump? Explain with neat sketches the function of air vessels in a reciprocating pump.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer from the following (any seven):
Where is a water hammer developed?
Reciprocating pump has _____ efficiency compared to centrifugal pump.
The fluid coming into the centrifugal pump is accelerated by
Which of the following turbines will have the lowest number of blades in it?
What is the head of water available at turbine inlet in hydro-electric power plant called?
Impulse turbine requires
The ratio of actual whirl velocity to the ideal whirl velocity in the centrifugal compressor is called as
The mass flow rate of air compressed in axial flow compressor is _____ centrifugal compressor.
Compression efficiency is compared against
Jet propulsion works on the principle of
Q.2 Solve both questions :
A jet of water of diameter 10 cm strikes flat plate normally with velocity of 15 $ m/s $. The plate is moving with a velocity of 6 $ m/s $ in the direction of the jet and away from the jet. Find- (i) the force exerted by the jet on the plate; (ii) work done by the jet on the plate per second.
Obtain an expression for the force exerted by a jet of water (strikes at the centre) on a stationary curved plate.
Q.3 Solve both questions :
Show that the force exerted by a jet of water on moving inclined plane in the direction of jet is given by $ F_x = \rho a (V - u)^2 \sin^2 \theta $ where, $ a = $ area of jet, $ \theta = $ inclination of the plate with the jet and $ v = $ velocity of jet.
Show the general layout of a hydro-electric power plant and explain each component in brief.
Q.4 Solve both questions :
What do you mean by gross head, net head and efficiency of turbine? Explain the different types of efficiency of a turbine.
Prove that the work done per second per unit weight of water in a reaction turbine is given as $ \frac{1}{g}(V_{u_1}u_1 \pm V_{u_2}u_2) $ where, $ V_{u_1} $ and $ V_{u_2} $ are velocities of whirl at inlet and outlet; $ u_1 $ and $ u_2 $ are peripheral velocities at inlet and outlet.
Q.5 Solve both questions :
A Francis turbine working under a head of 30 m has a wheel diameter of 1.2 m at the entrance and 0.6 m at the exit. The vane angle at the entrance is $ 90^{\circ} $ and guide blade angle is $ 15^{\circ} $. The water at the exit leaves the vanes without any tangential velocity and the velocity of flow in the runner is constant. Neglecting the effect of draft tube and losses in the guide and runner passages, determine the speed of wheel in rpm and vane angle at the exit. State whether the speed calculated is synchronous or not. If not, what speed would you recommend to couple the turbine with an alternator of 50 cycles?
What is cavitation? How can it be avoided in reaction turbine?
Q.6 Solve both questions :
A turbine develops 3000 kW under head of 300 m. The overall efficiency of the turbine is 83%. If speed ratio = 0.46, $ C_v = 0.98 $ and specific speed is 165, then find the (i) type of turbine, (ii) diameter of the turbine and (iii) diameter of the jet.
Define slip, percentage slip and negative slip of a reciprocating pump.
How will you classify the reciprocating pumps?
Q.7 Solve both questions :
A double-acting reciprocating pump, running at 40 r.p.m., is discharging $ 1~m^3 $ of water per minute. The pump has a stroke of 400 mm. The diameter of the piston is 200 mm. The delivery and suction head are 20 m and 5 m respectively. Find the slip of the pump and power required to deliver the pump.
A centrifugal pump has the dimensions-inlet radius 80 mm, outlet radius 160 mm, width of impeller at the inlet = 50 mm, $ \beta_1 = 0.45 $ radian, $ \beta_2 = 0.25 $ radian, width of impeller at the outlet = 50 mm. Assuming shockless entry, determine the discharge and the head developed by the pump when the impeller rotates at 90 radian/second.
Q.8 Solve all three questions :
How will you obtain an expression for the minimum speed for starting a centrifugal pump?
What is the effect of atmospheric condition on the output of compressor?
Air is to be compressed in a single-stage reciprocating compressor from 1.013 bar and $ 15^{\circ}C $ to 7 bar. Calculate the indicated power required for a free air delivery of $ 0.3~m^3/min $, when the compression process is isentropic.
Q.9 Solve both questions :
Explain with a neat sketch actual $ p-V $ diagram for a two-stage reciprocating compressor.
A single-sided centrifugal compressor is to deliver 14 kg of air per second, when operating at a pressure ratio 4:1 and a speed of 12000 r.p.m. The total head inlet conditions may be taken as 288 K and 1.033 $ kgf/cm^2 $. Assuming a slip factor as 0.9, a power input factor 1.04 and an isentropic efficiency (based on total head) of 80%, estimate the overall diameter of the impeller. If the Mach number is not to exceed unity at the impeller tip and 50% of the losses are assumed to occur in the impeller, find the minimum possible depth of the diffuser.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer from the following (any seven):
Where is a water hammer developed?
Reciprocating pump has _____ efficiency compared to centrifugal pump.
The fluid coming into the centrifugal pump is accelerated by
Which of the following turbines will have the lowest number of blades in it?
What is the head of water available at turbine inlet in hydro-electric power plant called?
Impulse turbine requires
The ratio of actual whirl velocity to the ideal whirl velocity in the centrifugal compressor is called as
The mass flow rate of air compressed in axial flow compressor is _____ centrifugal compressor.
Compression efficiency is compared against
Jet propulsion works on the principle of
Q.2 Solve both questions :
A jet of water of diameter 10 cm strikes flat plate normally with velocity of 15 $ m/s $. The plate is moving with a velocity of 6 $ m/s $ in the direction of the jet and away from the jet. Find- (i) the force exerted by the jet on the plate; (ii) work done by the jet on the plate per second.
Obtain an expression for the force exerted by a jet of water (strikes at the centre) on a stationary curved plate.
Q.3 Solve both questions :
Show that the force exerted by a jet of water on moving inclined plane in the direction of jet is given by $ F_x = \rho a (V - u)^2 \sin^2 \theta $ where, $ a = $ area of jet, $ \theta = $ inclination of the plate with the jet and $ v = $ velocity of jet.
Show the general layout of a hydro-electric power plant and explain each component in brief.
Q.4 Solve both questions :
What do you mean by gross head, net head and efficiency of turbine? Explain the different types of efficiency of a turbine.
Prove that the work done per second per unit weight of water in a reaction turbine is given as $ \frac{1}{g}(V_{u_1}u_1 \pm V_{u_2}u_2) $ where, $ V_{u_1} $ and $ V_{u_2} $ are velocities of whirl at inlet and outlet; $ u_1 $ and $ u_2 $ are peripheral velocities at inlet and outlet.
Q.5 Solve both questions :
A Francis turbine working under a head of 30 m has a wheel diameter of 1.2 m at the entrance and 0.6 m at the exit. The vane angle at the entrance is $ 90^{\circ} $ and guide blade angle is $ 15^{\circ} $. The water at the exit leaves the vanes without any tangential velocity and the velocity of flow in the runner is constant. Neglecting the effect of draft tube and losses in the guide and runner passages, determine the speed of wheel in rpm and vane angle at the exit. State whether the speed calculated is synchronous or not. If not, what speed would you recommend to couple the turbine with an alternator of 50 cycles?
What is cavitation? How can it be avoided in reaction turbine?
Q.6 Solve both questions :
A turbine develops 3000 kW under head of 300 m. The overall efficiency of the turbine is 83%. If speed ratio = 0.46, $ C_v = 0.98 $ and specific speed is 165, then find the (i) type of turbine, (ii) diameter of the turbine and (iii) diameter of the jet.
Define slip, percentage slip and negative slip of a reciprocating pump.
How will you classify the reciprocating pumps?
Q.7 Solve both questions :
A double-acting reciprocating pump, running at 40 r.p.m., is discharging $ 1~m^3 $ of water per minute. The pump has a stroke of 400 mm. The diameter of the piston is 200 mm. The delivery and suction head are 20 m and 5 m respectively. Find the slip of the pump and power required to deliver the pump.
A centrifugal pump has the dimensions-inlet radius 80 mm, outlet radius 160 mm, width of impeller at the inlet = 50 mm, $ \beta_1 = 0.45 $ radian, $ \beta_2 = 0.25 $ radian, width of impeller at the outlet = 50 mm. Assuming shockless entry, determine the discharge and the head developed by the pump when the impeller rotates at 90 radian/second.
Q.8 Solve all three questions :
How will you obtain an expression for the minimum speed for starting a centrifugal pump?
What is the effect of atmospheric condition on the output of compressor?
Air is to be compressed in a single-stage reciprocating compressor from 1.013 bar and $ 15^{\circ}C $ to 7 bar. Calculate the indicated power required for a free air delivery of $ 0.3~m^3/min $, when the compression process is isentropic.
Q.9 Solve both questions :
Explain with a neat sketch actual $ p-V $ diagram for a two-stage reciprocating compressor.
A single-sided centrifugal compressor is to deliver 14 kg of air per second, when operating at a pressure ratio 4:1 and a speed of 12000 r.p.m. The total head inlet conditions may be taken as 288 K and 1.033 $ kgf/cm^2 $. Assuming a slip factor as 0.9, a power input factor 1.04 and an isentropic efficiency (based on total head) of 80%, estimate the overall diameter of the impeller. If the Mach number is not to exceed unity at the impeller tip and 50% of the losses are assumed to occur in the impeller, find the minimum possible depth of the diffuser.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer from the following (any seven):
The force of impingement of a jet on a vane increases, if
A jet of water issues from a nozzle with a velocity of 20 m/s and it impinges normally on a flat plate moving away from it at $ 10~m/s $. If the cross-sectional area of the jet is $ 0.02~m^2 $ and the density of water is taken as $ 1000~kg/m^3 $, then the force developed on the plate will be
Kaplan turbine is
Cavitation in a hydraulic turbine is most likely to occur at the turbine
Euler equation for water turbine is derived on the basis of
A Francis turbine is coupled to an alternator to generate electricity with a frequency of 50 Hz. If the alternator has 12 poles, then the turbine should be regulated to run at which one of the following constant speeds?
Consider the following types of water turbines: 1. Bulb, 2. Francis, 3. Kaplan, 4. Pelton. One correct sequence of order in which the operating head decreases while developing the same power is
When the speed of a centrifugal pump is doubled, the power required to drive the pump will
A centrifugal pump driven by a directly coupled 3 kW motor of 1450 r.p.m. speed is proposed to be connected to another motor of 2900 r.p.m. speed. The power of the motor should be
Air vessel is used in a reciprocating pump to obtain
Q.2 Solve both questions :
Differentiate between impact of jet and jet propulsion. Show that the force exerted by a jet of water on moving inclined plate in the direction of jet is given by $ F_x = \rho a (V-u)^2 \sin^2 \theta $ where a is area of jet, V is velocity of jet and $ \theta $ is inclination of the plate with the jet.
A 75 mm diameter jet having a velocity of $ 30~m/s $ strikes a flat plate, the normal of which is inclined at $ 45^{\circ} $ to the axis of the jet. Find the normal pressure on the plate when the plate is stationary, when the plate is moving with a velocity of $ 15~m/s $ in the direction of jet, away from the jet and also determine the efficiency of the jet when the plate is moving.
Q.3 Solve both questions :
Derive Euler's equation of motion. Also derive Bernoulli's equation with the help of Euler's equation.
A pipe 200 m long slopes down at 1 in 100 and tapers from 600 mm diameter at the higher end to 300 mm diameter at the lower end, and carries $ 100~litres/s $ of oil (specific gravity 0.8). If the pressure gauge at the higher end reads $ 60~kN/m^2 $, calculate velocities at the two ends and pressure at the lower end neglecting all the losses.
Q.4 Solve both questions :
What is a hydraulic turbine? How are they classified? With the help of neat sketch, explain the construction and working of a Pelton wheel turbine.
An inward flow reaction turbine has external and internal diameters as 1 m and 0.5 m respectively. The turbine is running at 200 r.p.m. and width of turbine at inlet is 200 mm. The velocity of flow through the runner is constant and is equal to $ 1.8~m/s $. The guide blades make an angle of $ 10^{\circ} $ to the tangent of the wheel and the discharge at the outlet of the turbine is radial. Calculate all velocity vectors and draw the inlet and outlet velocity triangles. Also calculate mass flow through the runner/second, power developed and hydraulic efficiency.
Q.5 Solve both questions :
What is model analysis? What are the advantages and applications of model testing?
A 1:8 model of a 12 ft diameter turbine is operated at 600 r.p.m. under a net head of 54.0 ft. Under this mode of operation, the bhp and Q of the model were observed, to be 332 hp and 62 cfs, respectively. From the above data, compute (i) the specific speed of the model and the value of $ \sigma $, (ii) the efficiency and shaft torque of the model, (iii) the efficiency of the prototype, (iv) the flow rate and horsepower of the prototype if it is operated at 450 r.p.m. under a net head of 200 ft.
Q.6 Solve both questions :
What is negative slip in a reciprocating pump? Explain with neat sketches the functions of air vessels in a reciprocating pump.
The diameter and stroke length of a single-acting reciprocating pump are 75 mm and 150 mm respectively. It takes its supply of water from a sump 3 m below the pump through a pipe 5 m long and 40 mm in diameter. It delivers water to a tank 12 m above the pump through a pipe 30 mm in diameter and 15 m long. If separation occurs 75 kN/$ m^2 $ below the atmospheric pressure, find the maximum speed at which pump may be operated without separation. Assume that the piston has a simple harmonic motion.
Q.7 Solve both questions :
With the help of neat sketch, discuss various components and working of a volute type centrifugal pump.
A centrifugal pump is running at 1000 r.p.m. The outlet vane angle of the impeller is $ 30^{\circ} $ and the velocity of flow at outlet is $ 3~m/s $. The pump is working against a total head of 30 m and the discharge through the pump is $ 0.3~m^3/s $. If the manometric efficiency of the pump is 75%, determine (i) the diameter of the impeller and (ii) width of the impeller at the outlet.
Q.8 Solve both questions :
What are reciprocating compressors? Calculate the isothermal and adiabatic work and efficiency of a single-stage reciprocating compressor.
A two-stage single reciprocating compressor takes in air at the rate of $ 2~m^3/s $. The intake temperature and pressure of air are 0.1 MPa and $ 16^{\circ}C $. The air is compressed to a final pressure of 0.7 MPa. The intermediate pressure is ideal and cooling is perfect. The compression index in both the stages is 1.25 and the compressor runs at 600 r.p.m. Neglect clearance. Determine intermediate pressure, total volume of each cylinder, power required to drive the compressor and rate of heat rejection in the intercooler.
Q.9 Solve both questions :
What are centrifugal compressors? With the help of velocity diagram, deduce the expression of work done and pressure rise in centrifugal compressor.
A centrifugal compressor runs at a speed of 15000 r.p.m. and delivers 30 kg of air per second. Exit radius is 0.35 m, relative velocity at exit is $ 100~m/s $ at an exit angle of $ 75^{\circ} $. Assume axial inlet and $ T_{01}=300~K $ and $ P_{01}=1~bar $. Calculate (i) the torque, (ii) the power required to drive the compressor, (iii) the ideal head developed (iv) the work done and (v) the exit total pressure.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer from the following (any seven):
The force of impingement of a jet on a vane increases, if
A jet of water issues from a nozzle with a velocity of 20 m/s and it impinges normally on a flat plate moving away from it at $ 10~m/s $. If the cross-sectional area of the jet is $ 0.02~m^2 $ and the density of water is taken as $ 1000~kg/m^3 $, then the force developed on the plate will be
Kaplan turbine is
Cavitation in a hydraulic turbine is most likely to occur at the turbine
Euler equation for water turbine is derived on the basis of
A Francis turbine is coupled to an alternator to generate electricity with a frequency of 50 Hz. If the alternator has 12 poles, then the turbine should be regulated to run at which one of the following constant speeds?
Consider the following types of water turbines: 1. Bulb, 2. Francis, 3. Kaplan, 4. Pelton. One correct sequence of order in which the operating head decreases while developing the same power is
When the speed of a centrifugal pump is doubled, the power required to drive the pump will
A centrifugal pump driven by a directly coupled 3 kW motor of 1450 r.p.m. speed is proposed to be connected to another motor of 2900 r.p.m. speed. The power of the motor should be
Air vessel is used in a reciprocating pump to obtain
Q.2 Solve both questions :
Differentiate between impact of jet and jet propulsion. Show that the force exerted by a jet of water on moving inclined plate in the direction of jet is given by $ F_x = \rho a (V-u)^2 \sin^2 \theta $ where a is area of jet, V is velocity of jet and $ \theta $ is inclination of the plate with the jet.
A 75 mm diameter jet having a velocity of $ 30~m/s $ strikes a flat plate, the normal of which is inclined at $ 45^{\circ} $ to the axis of the jet. Find the normal pressure on the plate when the plate is stationary, when the plate is moving with a velocity of $ 15~m/s $ in the direction of jet, away from the jet and also determine the efficiency of the jet when the plate is moving.
Q.3 Solve both questions :
Derive Euler's equation of motion. Also derive Bernoulli's equation with the help of Euler's equation.
A pipe 200 m long slopes down at 1 in 100 and tapers from 600 mm diameter at the higher end to 300 mm diameter at the lower end, and carries $ 100~litres/s $ of oil (specific gravity 0.8). If the pressure gauge at the higher end reads $ 60~kN/m^2 $, calculate velocities at the two ends and pressure at the lower end neglecting all the losses.
Q.4 Solve both questions :
What is a hydraulic turbine? How are they classified? With the help of neat sketch, explain the construction and working of a Pelton wheel turbine.
An inward flow reaction turbine has external and internal diameters as 1 m and 0.5 m respectively. The turbine is running at 200 r.p.m. and width of turbine at inlet is 200 mm. The velocity of flow through the runner is constant and is equal to $ 1.8~m/s $. The guide blades make an angle of $ 10^{\circ} $ to the tangent of the wheel and the discharge at the outlet of the turbine is radial. Calculate all velocity vectors and draw the inlet and outlet velocity triangles. Also calculate mass flow through the runner/second, power developed and hydraulic efficiency.
Q.5 Solve both questions :
What is model analysis? What are the advantages and applications of model testing?
A 1:8 model of a 12 ft diameter turbine is operated at 600 r.p.m. under a net head of 54.0 ft. Under this mode of operation, the bhp and Q of the model were observed, to be 332 hp and 62 cfs, respectively. From the above data, compute (i) the specific speed of the model and the value of $ \sigma $, (ii) the efficiency and shaft torque of the model, (iii) the efficiency of the prototype, (iv) the flow rate and horsepower of the prototype if it is operated at 450 r.p.m. under a net head of 200 ft.
Q.6 Solve both questions :
What is negative slip in a reciprocating pump? Explain with neat sketches the functions of air vessels in a reciprocating pump.
The diameter and stroke length of a single-acting reciprocating pump are 75 mm and 150 mm respectively. It takes its supply of water from a sump 3 m below the pump through a pipe 5 m long and 40 mm in diameter. It delivers water to a tank 12 m above the pump through a pipe 30 mm in diameter and 15 m long. If separation occurs 75 kN/$ m^2 $ below the atmospheric pressure, find the maximum speed at which pump may be operated without separation. Assume that the piston has a simple harmonic motion.
Q.7 Solve both questions :
With the help of neat sketch, discuss various components and working of a volute type centrifugal pump.
A centrifugal pump is running at 1000 r.p.m. The outlet vane angle of the impeller is $ 30^{\circ} $ and the velocity of flow at outlet is $ 3~m/s $. The pump is working against a total head of 30 m and the discharge through the pump is $ 0.3~m^3/s $. If the manometric efficiency of the pump is 75%, determine (i) the diameter of the impeller and (ii) width of the impeller at the outlet.
Q.8 Solve both questions :
What are reciprocating compressors? Calculate the isothermal and adiabatic work and efficiency of a single-stage reciprocating compressor.
A two-stage single reciprocating compressor takes in air at the rate of $ 2~m^3/s $. The intake temperature and pressure of air are 0.1 MPa and $ 16^{\circ}C $. The air is compressed to a final pressure of 0.7 MPa. The intermediate pressure is ideal and cooling is perfect. The compression index in both the stages is 1.25 and the compressor runs at 600 r.p.m. Neglect clearance. Determine intermediate pressure, total volume of each cylinder, power required to drive the compressor and rate of heat rejection in the intercooler.
Q.9 Solve both questions :
What are centrifugal compressors? With the help of velocity diagram, deduce the expression of work done and pressure rise in centrifugal compressor.
A centrifugal compressor runs at a speed of 15000 r.p.m. and delivers 30 kg of air per second. Exit radius is 0.35 m, relative velocity at exit is $ 100~m/s $ at an exit angle of $ 75^{\circ} $. Assume axial inlet and $ T_{01}=300~K $ and $ P_{01}=1~bar $. Calculate (i) the torque, (ii) the power required to drive the compressor, (iii) the ideal head developed (iv) the work done and (v) the exit total pressure.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Questions
Choose the correct answer of the following (any seven) :
A free water jet acts upon a water wheel that has semi-circular vanes fitted on its periphery. The theoretical maximum efficiency of this wheel system is
The unit speed of a turbine having a rotational speed of and head is equal to
Specific speed of a turbine is defined as the speed of a member of same homologous series of such a size that it
What does Euler's equation of turbo machines relate to?
In a Francis turbine, the runner blades are radial at the inlet and the discharge leaves the runner radially at the exit. For this turbine
Without residual whirl in the flow at the entrance to a draft tube, the best cone angle is
A Kaplan turbine is
A centrifugal pump is started with its delivery valve kept
The indicator diagram of a reciprocating pump is a plot of
A centrifugal jet pump is classified as
Answer the following:
Explain the similarity laws for turbines.
A diameter jet of water strikes a curved vane with a velocity of . The inlet angle of the vane is zero and the outlet angle is measured with respect to the impinging jet direction. Determine the resultant force on the vane when the vane is stationary.
An inward-flow reaction turbine has an inlet guide vane angle of and inward edges of the runner blade at to the direction of rotation. The breadth of the runner at the inlet is a quarter of the inlet diameter and there is no whirl velocity at the outlet. The gross head is and the speed is The hydraulic and overall efficiencies may be assumed to be and respectively. Estimate the runner diameter at inlet and the power developed.
Answer the following:
What are the different characteristics of Francis turbine? Discuss any one of them.
A Francis turbine develops at an efficiency of under a net head of . The draft tube used in this setup is a vertical cylindrical pipe of diameter. (a) What increase in power could be expected if a tapering vertical draft tube having an outlet diameter of replaces the existing cylindrical draft tube? (b) What would be the increase in the overall efficiency? Assume that the head, speed and discharge remain the same and there are no additional friction losses due to the new draft tube.
Answer the following:
Explain different component parts of a centrifugal pump.
A centrifugal pump delivers water at the rate of for a total head of . Find the output of the pump. If the overall efficiency of the set consisting of the pump and the electric motor is , find the power required to drive the motor.
A centrifugal pump is required to discharge of water and develop a head of when the impeller rotates at The manometric efficiency is . The loss of head in the pump due to fluid resistance can be assumed to be where, velocity with which the water leaves the impeller. Water enters the impeller without shock and whirl and the velocity of flow is . Determine the (a) impeller diameter, (b) blade angle at outlet and (c) outlet area.
Answer the following:
Define slip in a reciprocating pump. Explain the phenomenon of negative slip.
A single-acting reciprocating pump has a plunger of diameter of and stroke of . If the speed of the pump is and if it delivers of water against a suction head of and a delivery head of , find the theoretical discharge, coefficient of discharge, slip, the percentage slip of the pump and the power required to drive the pump.
A scale model of a prototype air compressor consuming and running at a speed of delivers a flow rate of through a pressure ratio of . At dynamically and kinematically similar conditions, what would the operating speed, mass flow rate and power consumption be for the full-scale prototype?
Write short notes on any two of the following :
Draft tube
Turbine
Specific speed of pump
Priming of a pump
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Questions
Define the following terms (any seven) :
Jet Impingement
Nozzle
Penstock
Propeller Turbine
Head Race
Unit Discharge
Scroll Casing
Runner
Mechanical Efficiency of a Pump
Guide Vane Angle
Answer the following:
A jet of water, in diameter, issues with a velocity of and impinges on a series of vanes. The vanes are so arranged that each vane appears successively before that jet in the same position and always moves with velocity of . Find force on the plate, work done and the efficiency of system.
A jet of water having a velocity of impinges without shock on a series of vanes moving at . The direction of motion of the vanes is inclined at to that of the jet, the relative velocity at outlet is of that at inlet, and the absolute velocity of the water at the exit is to be normal to the motion of vanes, find (i) vane angles at entrance and exit; (ii) work done on vanes per kg of water supplied by the jet; and (iii) hydraulic efficiency.
Answer the following:
What is the basis of selection of a turbine at a particular place?
A turbine develops under a head of . The overall efficiency of the turbine is . If speed ratio = , and specific speed is , then find the (i) Type of turbine, (ii) Diameter of the turbine, and (iii) Diameter of the jet.
Answer the following:
Define the specific speed of a Turbine. Derive an expression for the specific speed.
Prove that the work done per second per unit weight of water in a reaction turbine is given as: $$\frac{1}{g}(V_{w1} u_1 \pm V_{w2} u_2)$$ Where, and velocities of whirl at inlet and outlet.
Answer the following:
What is a Draft tube? Explain with neat sketch.
A Francis turbine working under a head of has a wheel diameter of at the entrance and at the exit. The vane angle at the entrance is and guide blade angle is . The water at the exit leaves the vanes without any tangential velocity and the velocity of flow in the runner is constant. neglecting the effect of draft tube and losses in the guide and runner passages, determine the speed of wheel in r.p.m. and vane angle at the exit. State whether the speed calculated is synchronous or not. If not, what speed would you recommend to couple the turbine with an alternator of ?
Answer the following:
What do you understand by characteristics curves of a pump? Explain with sketch.
A centrifugal pump has the following dimensions: inlet radius = , outlet radius = , width of impeller at the inlet = , , . Width of impeller at the outlet = . Assuming shockless entry and determine the discharge and the head developed by the pump when the impeller rotates at .
Answer the following:
What are the causes of cavitation? How will you prevent the cavitation in hydraulic Machines?
Define Indicator diagram. How will you prove that area of indicator diagram is proportional to the work done by the reciprocating pump?
Answer the following:
How will you classify the reciprocating pump?
The cylinder bore diameter of a single acting reciprocating pump is and its stroke is . The pump runs at and lifts water through a height of . the delivery pipe is long and in diameter. Find the theoretical discharge and the theoretical power required to run the pump. If the actual discharge is , find the percentage slip. Also, determine the acceleration head at the beginning and middle of the delivery stroke.
Answer the following:
A single inlet-type centrifugal compressor handles of air. The ambient air condition are and . The compressor runs at with isentropic efficiency of . The air is compressed in the compressor from static pressure to total pressure. The air enters the impeller eye with a velocity of with no prewhirl. Assuming that the ratio of whirl speed to tip speed is , calculate: (i) Rise in total temperature during compression if the change in K.E. is negligible (ii) The tip diameter of the impeller (iii) Power required (iv) Eye diameter if the hub diameter is .
What is a centrifugal compressor? How does it differ from an axial flow compressor?
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Questions
Define the following terms (any seven) :
Gross head
Net head
Inward radial flow turbine
Outward radial flow turbine
Unit speed
Unit discharge
Draft tube
Manometric efficiency
Air vessel
Slip
Answer the following:
Obtain an expression for the force exerted by a jet of water on a fixed vertical plate in the direction of jet.
A jet of water of diameter moving with a velocity of strikes a fixed plate in such a way that the angle between the jet and plate is . Find the force exerted by jet on the plate— (i) in the direction normal to the plate; (ii) in the direction of jet.
A jet of water of diameter strikes a flat plate normally with a velocity of . The plate is moving with a velocity of in the direction of jet and away from the jet. Find— (i) force exerted by jet on the plate; (ii) work done by jet on the plate per second.
Answer the following:
Describe briefly the function of various components of Pelton turbine with neat sketches.
A Pelton wheel has mean bucket speed of with a jet of water flowing at the rate of under a head of . The buckets deflect the jet through an angle of . Calculate the power given by water to the runner and hydraulic efficiency of the turbine. Assume coefficient of velocity as .
Answer the following:
How is hydraulic turbine classified?
A Francis turbine with an overall efficiency of is required to produce power. It is working under a head of . The peripheral velocity is and radial velocity of flow at inlet is . The wheel runs at and the hydraulic losses in the turbine are of the available energy. Assuming radial discharge, determine— (i) guide blade angle; (ii) the wheel vane angle at inlet; (iii) diameter of wheel at inlet; (iv) width of wheel at inlet.
Answer the following:
Define the term 'unit power'. Also derive the expression for this term.
A turbine is to operate under a head of at The discharge is . If the efficiency is , determine the performance of the turbine under a head of .
Answer the following:
Describe the working of a single-acting reciprocating pump with neat sketch.
A single-acting reciprocating pump, running at , delivers of water. The diameter of piston is and stroke length is . Determine— (i) theoretical discharge; (ii) coefficient of discharge; (iii) slip and the percentage slip of the pump.
Answer the following:
Describe multistage centrifugal pump with (i) impellers in parallel and (ii) impellers in series.
A centrifugal pump having outer diameter equal to two times the inner diameter and running at , works against a total head of . The velocity of flow through the impeller is constant and equal to . The vanes are set back at angle of at outlet if the outer diameter of the impeller is and width at outlet is . Determine— (i) vane angle at inlet; (ii) work done by impeller on water per second; (iii) manometric efficiency.
Answer the following:
Describe the working of a single-stage reciprocating air compressor.
Estimate the work done by a two-stage reciprocating single-acting air compressor to compress of air per min at and to a final pressure of . The intermediate receiver cools the air to and . For air, take .
Write short notes on the following :
Governing of water turbine
Indicator diagram
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Questions
Write on the following in short, preferably one or two sentences each (any seven) :
Suction head
Delivery head
Static head
Priming
Multistage pump
Stay ring
Mechanical efficiency
Fluid
Power required to drive pump
Manometric efficiency
Answer the following:
Explain the function of Francis turbine.
A Francis turbine works under a head of and develops at a speed of The volume flow rate through the machine is . If the outside wheel diameter is and the axial wheel width at the inlet is , find the overall efficiency of the turbine, its hydraulic efficiency, ($\eta_h$), and the inlet angles of the guide blades and the rotor blades. Assume a volumetric efficiency of and the velocity at the draft tube exit to be . The whirl velocity component at the wheel exit is zero.
Answer the following:
Differentiate between inward-flow and outward-flow reaction turbines.
The total resistance offered to the motion of a jet-propelled boat is . The boat is moving with a velocity of and draws water amid ship. The water is discharged through two jets provided at the back of the ship. The diameter of each jet is . Determine the efficiency of jet propulsion.
Answer the following:
Obtain an expression for unit speed, unit discharge and unit power for a turbine.
An inward-flow reaction turbine having an overall efficiency of is required to deliver . The head (H$) is $16\text{ m} and the peripheral velocity is . The radial velocity of flow at inlet is . The runner rotates at The hydraulic losses in the turbine are of the available energy. Determine (i) the diameter of the runner, (ii) the guide vane angle, and (iii) the runner blade angle at inlet and through the turbine. Assume the discharge from the runner is radial.
Answer the following:
Explain the purposes of providing (i) scroll casing, (ii) stay vanes, and (iii) guide vanes for a reaction turbine.
Dimensions of a centrifugal pump impeller are given below :
| Parameter | Inlet section | Outlet section |
|---|---|---|
| Radius, | ||
| Blade width, | ||
| Blade angle, |
The pump handles water and is driven at Calculate the theoretical head and mechanical power input if the flow rate is .
Answer the following:
What is cavitation? Why and how can it be avoided? Where does it occur? Also explain net positive suction head (NPSH). Explain, in detail, in the context of a pump.
A Francis turbine with an overall efficiency of is required to produce . It is working under a head of . The peripheral velocity is and the radial velocity of flow at inlet is . The wheel runs at and the hydraulic losses in the turbine are of the available energy. Assuming radial discharge, determine the guide blade angle, the wheel vane angle at inlet, diameter of the wheel at inlet, and width of the wheel at inlet.
Answer the following:
Derive an expression for the starting speed of the centrifugal pump.
A centrifugal pump lifts water against a static head of of which is suction. The suction and delivery pipes are both in diameter. The head loss in the suction pipe is and in the delivery pipe is . The impeller is in diameter and wide and runs at The blade angle at exit is . If the manometric efficiency is and mechanical efficiency is , determine the power required to drive the pump and discharge.
A centrifugal compressor is desired to have a total pressure ratio of . The inlet eye of the compressor impeller is in diameter. The axial velocity at inlet is and the mass flow is . The velocity in the delivery duct is . The tip speed of the impeller is and runs at with total head isentropic efficiency of and pressure coefficient . The ambient conditions are and . Calculate— (a) static pressure ratio; (b) static pressure and temperature at outlet of the compressor; (c) work of the compressor per kg of air; (d) theoretical power required to drive the compressor.
Write short notes on any two of the following :
Draft tube
Turbine
Specific speed
Centrifugal pump
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
- Assume any suitable data, if required.
Q.1 Define the following in short, preferably one or two sentences each (any seven) :
Fluid
Guide vanes
Draft tube
Turbo means
Hydraulic turbine
Stay ring
Mechanical efficiency
Specific speed
Centrifugal pump
Manometric head
Q.2 Solve both questions :
Explain the classification of fluid machineries.
Establish the ratio of forces exerted by a water jet when it is made to strike— (i) a stationary flat plate held normal to it; (ii) a flat plate moving in the direction of jet at one-third the velocity of jet; (iii) a series of flat plates mounted on a wheel and moving at one-third the velocity of jet.
Q.3 Solve both questions :
Briefly explain the different types of turbine and write the advantages of each.
A velocity jet of water strikes without shock a series of vanes moving at . The jet is inclined at an angle of to the direction of motion of vanes. The relative velocity of jet at outlet is 0.9 times of the value at inlet and the absolute velocity of water at exit is to be normal to the motion of vanes. Determine (i) the vane angles at entrance and exit, (ii) the work done on vanes per second per N of water supplied by the jet and (iii) the hydraulic efficiency.
Q.4 Solve both questions :
Show that the efficiency of a Pelton wheel will be maximum when the velocity of the wheel is half the velocity of the jet of water at inlet.
An inward flow reaction turbine having an overall efficiency of 80% is required to deliver . The head is and the peripheral velocity is . The radial velocity of flow at inlet is . The runner rotates at The hydraulic losses in the turbine are 15% of the available energy. Determine (i) the diameter of the runner, (ii) the guide vane angle, (iii) the runner blade angle at inlet and through the turbine. Assume the discharge from the runner is radial.
Q.5 Solve both questions :
Explain the purpose of providing (i) scroll casing, (ii) stay vanes and (iii) guide vanes for a reaction turbine.
A Pelton wheel has to develop under a net head of while running at a speed of If the coefficient of the jet , speed ratio and the ratio of the jet diameter is of the wheel diameter, calculate the number of jets required for the Pelton wheel. Also calculate (i) the diameter of jet, (ii) the diameter of pitch circle and (iii) the quantity of water supplied to the wheel.
Q.6 Solve both questions :
Differentiate between centrifugal and reciprocating pump.
A centrifugal pump having an impeller outside diameter rotates at The vanes are radial at exit and wide. The velocity of radial flow through the impeller is . The velocities in the suction and delivery pipes are and respectively. Neglecting frictional losses, determine the height through which the pump lifts, and the horsepower of the pump. Assume radial entry.
Q.7 Solve both questions :
Explain the different efficiencies used in centrifugal pump.
A centrifugal pump lifts water against a static head of of which is suction. The suction and delivery pipes are both in diameter. The head loss in the suction pipe is and in the delivery pipe . The impeller is in diameter, wide and runs at The blade angle at exit is . If the manometric efficiency is 80% and mechanical efficiency 70%, determine the power required to drive the pump and discharge.
Q.8 Solve the following question :
A centrifugal compressor is desired to have a total pressure ratio of 4. The inlet eye of the compressor impeller is in diameter. The axial velocity at inlet is and the mass flow is . The velocity in the delivery duct is . The tip speed of the impeller is and runs at with total head isentropic efficiency of 78% and pressure coefficient 0.72. The ambient conditions are and . Calculate— (a) the static pressure ratio; (b) the static pressure and temperature at outlet of compressor; (c) the work of compressor per kg of air; (d) the theoretical power required to drive compressor.
Q.9 Write short notes on any two of the following :
Relief valve
Electrohydraulic governor
Priming of a pump
Instructions:
- All questions carry equal marks.
- There are TEN questions in this paper.
- Attempt any FIVE questions.
Questions
Write a note on the application of the moment of momentum equation to flow through hydraulic machinery. Also explain Euler's fundamental equation.
The following data is given for a Francis turbine: Net head = 70 m Speed = 600 r.p.m. Shaft power = 367.875 kW $\eta_o = 85%$ $\eta_h = 95%$ Flow ratio = 0.25 Breadth ratio = 0.1 Outer diameter of the runner = 2 x inner diameter of the runner The thickness of vanes occupy 10% of the circumferential area of the runner Velocity of flow is constant at inlet and outlet and discharge is radial at outlet Determine— (a) guide blade angle; (b) runner vane angles at inlet and outlet; (c) diameter of runner at inlet and outlet; (d) width of wheel at inlet.
A Kaplan turbine working under a head of 30 m develops 1290 kW SP. If the— speed ratio = 2.1 flow ratio = 0.62 diameter of boss = 0.34 times the diameter of the runner overall efficiency of the turbine = 89% find the diameter of the runner and the speed of the turbine.
A Pelton wheel is revolving at a speed of 200 r.p.m. and develops 5886 kW SP when working under a head of 200 m with an overall efficiency of 80%. Determine unit speed, unit discharge and unit power. The speed ratio of the turbine is given as 0.48. Find the speed, discharge and power when this turbine is working under a head of 150 m.
Write a note on performance characteristics and testing of models and selection of water turbines.
Write a note on surging, choking and stalling in rotary compressors.
The diameter of an impeller of a centrifugal pump at inlet and outlet are 300 mm and 600 mm respectively. The velocity of flow at outlet is 2.5 m/s and vanes are set back at an angle of at outlet. Determine the minimum starting speed of the pump if the manometric efficiency is 80%.
A centrifugal pump is running at 1000 r.p.m. The outlet vane angle of the impeller is and velocity of flow at outlet is 3 m/s. The pump is working against a total head of 30 m and the discharge through the pump is . If the manometric efficiency of the pump is 75%, determine the— (a) diameter of the impeller; (b) width of the impeller at outlet.
A double acting reciprocating pump, running at 50 r.p.m. is discharging 900 litres of water per minute. The pump has stroke of 400 mm. The diameter of piston is 250 mm. The delivery and suction heads are 25 m and 4 m respectively. Find the slip of the pump and power required to drive the pump.
Write a note on the theory of hydraulic couplings and torque converters, operating characteristics and common uses.