FLUID MECHANICS AND HYDRAULIC MACHINES Model Papers JNTUH

             MODEL PAPER 1

a)Explain the piezometer briefly with a neat sketch?

b)Explain briefly the mechanical gauges?

c)Define study and non-study, uniform and non-uniformed flows?

d)Derive the continuity equation?

e)Explain briefly the term boundary layer with a neat sketch?

f)Explain what is laminar sub layer?

g)What is hydraulic turbine?

h)What are the functions of draft tube?

i)What is a pump and how pumps are classified?

j)Describe the principle of working of centrifugal pump?

PART-B Marks: 50

1)A. Explain about U-Tube differential manometer?

b. A cylinder of 0.12m radius rotates concentrically inside a fixed cylinder of 0.13m radius.

Both the cylinders are 0.3m long. Determined the viscosity of fluid which fills the space

between the cylinders, if a torque of 0.88Nm is required to maintain an ang

ular velocity of

2π rad/sec.

OR

2)A pipeline is 15 cm in diameter and is at an elevation of 100 m at section A. At section B, it is

at an elevation of 107.0 m and has a diameter of 30 cm. When a discharge of 50 lit/sec of

water is passed through this pipe, the pressure at section A is observed to be 30KPa. The

energy loss in the pipe is 2 m. calculate the pressure at B when the flow is (i) from A to B,

(ii) from B to A.

3)a) Explain how the following flow problems are analyzed.

i) Series pipe connection

ii) Parallel pipe connection iii) Equivalent pipe connection.

b) Water flows through a 10cm diameter, 30m long pipe at a rate of 1400 rpm. What percent

of head would be gained by replacing the central one third length of pipe by another

pipe of 20cm diameter. Assume that the changes in section are abrupt and f = 0.008 for all pipes.

Neglect entrance and exit losses but consider major loss and losses due to sudden contraction

and sudden expansion.

OR

4) a) State and derive the momentum equation.

b) Discuss path line, stream line, streak line and stream tube with neat sketches.

5)Water flows through a 10cm diameter, 30m long pipe at a rate of 1400 rpm. What percent

of head would be gained by replacing the central o

ne third length of pipe by another pipe of

20cm diameter. Assume that the changes in section are abrupt and f = 0.008 for all pipes.

Neglect entrance and exit losses but consider major loss and losses due to sudden

contraction and sudden expansion.

OR

6)Derive an expression for finding the major loss when the fluid flows through a pipe. Also

give the formulae for various minor losses.

A 300mm x 150mm inclined venture meter carries water. The reading recorded by an

inverse U-tube manometer is 400mm. The specific gravity of the manometric fluid is 0.8. If

the loss between the inlet and throat is 0.3 times the kinetic head of the pipe, determine the

discharge and coefficient of discharge

7) A jet of water 120 mm in dia

meter and moving with a velocity of 25m/sec strikes normally

on a flat plate. Determine the power developed and the efficiency of the system when i) The

plate is stationary ii) The plate is moving with a velocity of 8m/sec in the direction of the

jet. And

iii).The plate is moving with a velocity of 8m/sec towards the jet.

OR

8)Derive an expression for the force exerted by a jet striking the curved plate at one end

tangentially when the plate is symmetrical.

9)Define Specific speed of a pump. Derive an expression for calculating the same. Give the

classification of pumps based on specific speed

OR

10)A centrifugal pump running at 1000r.p.m delivers water against a head of 14.5m.The vanes are curved

at an angle of 30 with its periphery. If the impeller diameter at the outlet is 30

cm and outlet width is 5 cm, determine the discharge. Take the Manometric efficiency as 95%.

      MODEL PAPER 2

1.Define gauge pressure and absolute pressure?

2.Explain about viscosity and kinematic viscosity?

3.What is stream line body and bluff body?

4.What are the assumptions made in derivation of Bernoulli’s theorem?

5.Differentiate between laminar and turbulent boundary layer?

6.What are minor losses in pipes?

7.State the advantagesof Kaplan turbine over Francis turbine?

8.What is function of governor in a turbine?

9.List the main components of the centrifugal pump and explain them with neat sketch?

10.What is air vessel and what are its uses?

Part-B

1)Define Surface tension. Explain how does it varies with variation in temperature in fluids

and explain how to determine the pressure intensity within a droplet and jet of liquid in

excess of the outside pressure intensity.

OR

2)A pipe having a length of 6 kmand diameter 0.7mconnects two reservoirs A and B, the

difference between their water levels is 30m. Halfway along the pipe there is a branch

through which water can be supplied to a third reservoir C. Taking f=0.024 determine the rate of flow of reservoir

B when on water is discharged to reservoir C.

3)i) State and derive the momentum equation.

ii)Discuss

path line, stream line, streak line and stream tube with neat sketches.

OR

4)a. Explain & derive Bernoulli’s theorem and also its assumptions?

5)Show that the discharge of water through a sharp edged orifice shall be increased by about

38% if a short cylindrical mouthpiece of the same diameter is fitted in to it on the outside of

the tank. Take coefficient of contraction as 0.62 and neglect the friction.

6)Derive an expression for finding the discharge through an orifice.

OR

7)Show that the efficiency of a free jet striking normally a series of flat plates mounted on the

periphery of a wheel never exceeds 50%.

OR

8)

i) Write a brief note on classification of turbines.

ii) A pelton wheel has to be designed for the following data: power to be developed =6000

kW, Net head available = 400 m, speed = 550 rpm, Ratio of jet diameter to the wheel

diameter = 1/10 and overall efficiency = 85%. Find the number of jets, diameter of jet,

diameter of the wheel and quantity of water required.

9)i) What is meant by Negative Slip? When does this occurs?

ii) A double acting reciprocating pump, running at 40 rpm is discharging 1.0 mof water per

minute. The pump has a stroke of 400mm. The diameter of the piston is 200mm. The

delivery and the suction heads are 20m and 5m respectively. Find the slip of the pump and

power required to drive the pump.

OR

10)Explain the classification of centrifugal pumps. Explain the working of a centrifugal pump?

     MODEL PAPER 3

a)What is surface tension?

b)Convert a pressure head of 100m water to kerosene of specific gravity 0.81

c)Explain stream line and path line?

d)Write the Euler’s and Bernoulli’s equations?

e)Write the methods of preventing the separation of boundary layer?

f)Explain about pitot tube?

g)Explain the force exerted on a stationary flat plate held normal to the jet?

h)What are the main parts of Francis turbine?

i)Write the losses in centrifugal pump?

j)Define the negative slip of a reciprocating pump?

PART-B Marks: 50

1)a) Define the following

i) Atmospheric pressure ii) Gauge pressure iii) Vacuum pressure iv) Absolute pressure

b) What are manometers and how are they classified? What is differential manometer?

OR

2)What is vapour pressure and cavitations? How does cavitations’ occurs and what it’s effects?

3)Classify the flows and explain them?

OR

4)Derive continuity equation in three dimensional flow?

5)What is boundary layer and explain about laminar and turbulent boundary layers?

OR

6)What is separation of boundary layer and what are the methods of preventing separation

of boundary layer?

7)a) Show that the efficiency of a free jet striking normally a series of flat plates mounted

on the periphery of a wheel never exceed 50%.

OR

8)Give the classification of turbines and explain each one in detail?

9)Explain the working of a reciprocating pump in detail?

OR

10)What are the performance characteristic curves of centrifugal pump and explain them?

   MODEL PAPER 4

a)What are the physical properties of the fluids?

b)Explain briefly about diaphragm gauge?

c)What are rotational and irrotational flows?

d)Explain about hydraulic gradient line?

e)What is meant by boundary layer thickness?

f)What is cavitation? How can it be avoided in reaction turbines?

g)Draw the velocity diagram for jet striking a moving curved vane tangentially at one tip and leaving at other?

h)What is the function of surge tank?

i)Define indicator diagram with neat sketch?

j)What are the efficiencies of centrifugal pump?

                                                        PART-BMarks: 50

1) A) What are the various types of fluids and define them?

b) How does viscosity of liquids and gasses vary with temperature?

OR

2)What are deferential manometers and explain them?

3)What are body forces, surface forces and line forces? explain them.

OR

4)What is momentum equation? Derive an expression for force exerted by

a flowing fluid on a pipe bend?

5)Define Drag and Lift? Derive an expression for Drag force and Lift force?

OR

6)Drive DARCY WEISBACK equations for frictional losses in pipe flow?

7)Derive an expression for work done on a series of radial curved vanes?

OR

8)Explain various types of characteristic curves of hydraulic turbine?

9) a) What is slip of a reciprocating pump and what is negative slip?

b) What is the indicator diagram of a reciprocating pump and explain?

OR’

10)a) Explain the term NPSH and how it is useful?

b) Derive an expression for specific speed of a centrifugal pump?

   MODEL PAPER 5

Marks: 25

a)Explain the piezometer briefly with a neat sketch?

b)Explain briefly the mechanical gauges?

c)Define study and non-study, uniform and non-uniformed flows?

d)What is stream line body andbluff body?

e)What are the assumptions made in derivation of Bernoulli’s theorem?

f)Differentiate between laminar and turbulent boundary layer?

g)Explain the force exerted on a stationary flat plate held normal to the jet?

h)What are the main parts of Francis turbine?

i)Write the losses in centrifugal pump?

j)Define the negative slip of a reciprocating pump?

k)

PART-B

1.

a) Define surface tension and derive the equation for pressure intensity inside liquid jet.

b) Explain the manometer that can be used for very precise measurement of small pressure

difference between two points with a neat sketch?

OR

2. a) Define Viscosity. Derive Newton’s equation of viscosity. Explain th

e variation of shear stress with velocity gradient in the case of various fluids. I

b) Calculate the capillary rise in a glass tube of 3.2 mm diameter when immersed vertically in

mercury. Take surface tension for mercury is 0.073 N/m.

3 .definestream line, path line , streak line and stream tube.

OR

4.Derive the equation of continuity for 3-Dimensional flows.

5. What are minor losses in pipes? Derive an expression loss of head due to sudden enlargement of pipe.

OR

6. Explain with a neat sketch the Hydraulic gradient line and Total energy line.

7. Derive the condition for max. power transmitted through the nozzle.

OR

8. Derive the condition for diameter of nozzle for max. power transmission.

9. What is geometric similarity? Explain about surge tank and Water hammer.

OR

10. List main component parts of a centrifugal pump and explain them briefly with a neat sketch

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