UNIT - I

1.

2 marks questions.

  1. Define turbulence?
  2. Define mixing length?
  3. What is equivalent length?
  4. Explain free turbulence and wall turbulence ?
  5. Explain laminar and turbulent flow?

2.

7 marks questions.

  1. For turbulent flow in pipes, cumpute the difference for the pipe wall at which the velocity is equal to the average velocity of flow.
  2. A 20cm diameter pipe conveys fresh water of specific weight 9.81KN/m3 .Measurement indicate that velocity at the pipe center and at a distance of 5cm from the pipe center are 2.75m/s. and 2.25m/s respectively. If the flow in the pipe is turbulent , calculate the shear friction velocity & the wall shear stress.
  3. A 30cm diameter main is required for a town water supply. As pipes over 250mm diameter are not readily available it was decided to lay two parallel mains of same diameter. Calculate the diameter of parallel pipes of same diameter.
  4. Determine the discharge from the pipe wall at which the local velocity is equal to the average velocity for turbulent flow in pipes.
  5. Derive velocity distribution equation for turbulent flow in smooth pipe.
  6. In a fully rough turbulent flow in a 15cm diameter pipe the center line velocity is 2.5m/s and the local velocity at mid radius is 2.28m/s. find the discharge and the height of the roughness projection.
  7. In a pipe of diameter 100mm, carrying water the velocities at the pipe center and 30mm from the pipe center are found to be 2.5m/s respectively. Find the wall shearing stress.

UNIT -2

1.

2 marks questions.

  1. Define boundary layer?
  2. Define laminar sublayer ?
  3. Write down expression for momentum thickness and energy thickness in boundary layer?
  4. What is the limit of Reynolds number for the boundary layer to change from laminar to turbulent in case of flood flow past a flat plate with zero angle of incidence?
  5. Define boundary line thickness?

2.

7 marks questions.

  1. A roughness thin board 25cm wide, 150cm long moves at 2.75m/s through water . The boundary layer is 5cm thick both sides at rear end of the board and the velocity distribution over the plate is given by the equation: u = y 1/4.Find the drag force in v0 δ Newton’s & express it as a pure number independent of thickness δ.
  2. Assuming the velocity distribution in the boundary layer as (u/v)=[2y/δ-(y/δ)2,determine the thickness of the boundary layer & the shear stress intensity at 0.75m from the leading edge & the drag force on one side of the plate 1m long &80m wide placed in water moving at a velocity of 0.25m/s. take µ=0.01 poise.
  3. A flate plate 1.2mx1.2m moves at 60kmph in stationary air of specific weight 1.5kg/m3. If the coefficient of drag and lift are 0.15&0.75 respectively ,determine

a)The lift force,

b)The drag force,

c)Power required to keep the plate in motion.

  1. Define energy thickness and derive expression for the same.
  2. A smooth float plate 1.5m wide and 20m long is subjected to flow of water along its length with a velocity of 2.5m/s. Find the:

a)Extent of the laminar boundary layer on the plate .

b)The thickness of the boundary layer at the edge of the laminar boundary layer. (Take e=998kg/m3 and ѵ= 1x10-6m2/s)

  1. A kite weighing 7.848N has an effective area of 0.8m2. It is maintained in air at an angles of 10° to the horizontal . The string attached to the kite makes an angle of 45°to the horizontal and at this position the value of co-efficient of drag and lift are 0.6 and 0.8 respectively. Find the speed of the wind and the tension in the string . Take the density of air as 1.25kg/m3.
  2. Distinguish between deformation drag surface and form drag. In the case of a sphere discuss their relative importance at various increasing values of Reyonlds number.

UNIT -3

1.

2 marks questions.

  1. Define critical flow in an open channel?
  2. Define specific energy?
  3. What is board crested weir?
  4. Define hydraulic jump?
  5. What do you understand by non-uniform flow of open channel?

2.

7marks questions.

  1. Derive the conditions for critical flow in an open channel.
  2. Derive the equation for maximum discharge over a broad crested weir.
  3. In a horizontal rectangular channel there occurs an hydraulic jump corresponding to an initial Froude number of 4.5 .

Determine the critical depth & head loss in terms of the initial depth yi .

  1. The discharge of water through a rectangular channel of width 8m, is 15m3/s when depth of flow is 1.2m. Calculate:
  1. Specific energy
  2. Critical depth and critical velocity .
  3. Minimum specific energy .
  1. Calculate the critical depth corresponding to a discharge of 6m3/s in:
  1. Rectangular channel of width 3m.
  2. Triangular channel of side slope 1.5 H:V.
  1. The depth of flow of water, at a certain section of a rectangular channel of 2m wide is 0.3m. The discharge through the channel is 1.5m3/s. Determine whether a hydraulic jump will occur ,and if so, find its height and loss of energy per kg of water.
  2. For critical flow show that the Froude number is unity.

UNIT – 4

1.

2 marks questions.

  1. Define Dynamic Similarity?
  2. Define Dimensional analysis?
  3. What is distorted model? Give any two advantages of distorted model.
  4. Define water hammer?
  5. Give one example each of fundamental unit and a derived .

2.

7 marks questions.

  1. The efficiency η of a fan depends on density ρ,viscosity μ , of the fluid , angular velocity ω, diameter D and discharge Q . Obtain a functional relationship for η .
  2. In a 1.25 model of a stilling basin the height of hydraulic jump in the model was observed to be 250mm. What is the height of jump in the prototype? If the energy dissipated in the field is 3600kw, what is the corresponding value in the model ?
  3. A concrete water main 3.2km long ,15cm radius discharges into a reservoir at the rate of 12x106lpd. If this line is gradually closed by operating a value at the reservoir end in 15 second s, show that there is possibility of pipe burst. The safe pressure for concrete pipe is 25 N/cm2.
  4. Explain the different dimensionless number and their significance.
  5. The frictional torque Т of a disc of diameter D rotating at a speed N in a fluid of viscosity μ and density ρ in a turbulent flow is given by:

T=D5N2ρФ[μ/D2Nρ]

Prove this by the method of dimensions.

  1. Obtain an expression for the rise in pressure in a thin elastic pipe of circular section in which the flow of water is stopped by sudden closure of valve.
  2. List all the variables that may influence the motion of a moving body fully submerged in a fluid and by dimensional analysis derive an expression for resistance of its motion .

UNIT -5

1.

2 marks questions.

  1. Define unit power ?
  2. Define specific speed ?
  3. Define turbine and pump?
  4. What is the functions of draft tube in hydroelectric project ?

2.

7 marks questions.

  1. With neat sketches explain different types of draft tubes.
  2. Derive the equation for the specific speed of a centrifugal pump.
  3. Write detailed note on classification of turbines.
  4. What are the different efficiencies of centrifugal pump?
  5. A pelton wheel is to be designed for the following specifications:

Power = 9560 kilo watt

Head = 350 m

Speed = 750 rpm

Overall efficiency = 85%

Jet diameter = not to exceed 1/6th of the wheel diameter

Determine the following

  1. The wheel diameter
  2. Diameter of the jet
  3. The no. of the jet

The Cv = .985, speed ratio = .45

  1. Tests were conducted on a francis turbine of 8m diameter under a head of 9m. the turbine running at 240rpm developed 85kw and the water consumption was 1.2m3/s. If the same turbine is operated under head of 16m, calculate the new speed ,discharge& power developed.
  2. Explain the following :
  1. Governing of turbine
  2. Draft tube
  3. Cavitations