## Applied Hydraulics - 2 - May 2014

### Civil Engineering (Semester 6)

TOTAL MARKS: 80

TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.

(2) Attempt any **three** from the remaining questions.

(3) Assume data if required.

(4) Figures to the right indicate full marks.

### Solve any four of the following

**1 (a)** Standing wave flume and venturi flume.(5 marks)
**1 (b)** Explain the surges in open channel.(5 marks)
**1 (c)** Explain the development of boundary layer.(5 marks)
**1 (d)** Write short notes on Aerofoils(5 marks)
**1 (e)** Boundary layer separation.(5 marks)
**2 (a)** Derive the dynamics equation for gradually varied flow.(10 marks)
**2 (b)** Calculate the friction drag on a plate 0.15m wide and 0.45m long placed longitudinally in a stream of oil flowing with a free stream velocity of 6 m/s. Also find the thk of the boundary layer and shear stress at the trailing edge. Sp.gr. Of oil is 0.925 and its kinematic viscosity is 0.9 stokes.(10 marks)
**3 (a)** A cylinder 1.2 m India. is rotated about its axis :1] air having a velocity of 128 km per hr.A lift of 5886 N per meter length of the cylinder is developed on the body.
Assuming ideal fluid theory, find the rotational speed and the location of the
stagnation points. Given p= 1.236 kg/m^{3}(10 marks)
**3 (b)** Show that the head loss in hydraulic jump formed in a rectangular channel may be expressed as

$$\Delta E=\dfrac{\left ( V1-V2 \right )^{3}}{2g\left ( V1+V2 \right )}$$(10 marks)
**4 (a)** A concrete lined rectangular channel is our wide and has a bed slope of l in 2500; It conveys water at rate of 10.90 01' sec at a depth of 0.75m. Determine for this discharge, the critical depth, the critical velocity and corresponding min specific energy head. Is a flow subcritical or supercritical? Find also the slope of water
surface.

Take Manning's N=0.015(10 marks)
**4 (b)** Derive an expression for lift acting on rotating cylinder.(10 marks)
**5 (a)** Design an irrigation channel in alluvial soil according to Lacey's silt theory given: following data

Slope of the channel = 1:5000

Lacey's silt factor = 0.9

Channel side slope 1/2 :1

Also find maximum discharge which can be allowed to flow in it.(12 marks)
**5 (b)** Compare Kennedy's theory and Lacey's theory.(8 marks)
**6 (a)** Show that the hydraulic mean depth of trapezoidal channel having the best proportion is half of the minimum depth.(10 marks)
**6 (b)** For a trapezoidal channel with bottom width 40m and side slopes 2H:1V. Mannings N=0.015 and bottom slope is 0.0002. If it carries 60m^{3} discharges, determine the normal depth.(10 marks)
**7 (a)** For the velocity profile in laminar boundary u/U =3/2(y/δ)-1/2(y/δ)^{3} find the thk of boundary layer and shear stress 1.8m from the leading edge of the plate. The plate is 2.5m long and 1.5m wide and is placed in water moving with velocity of 15m/s. Find drag on one side of plate μ_{water}=0.01 poise.(10 marks)

### Write a short note

**7 (b) (1)** Specific energy curve.(5 marks)
**7 (b) (2)** Steady and unsteady flow in case of channels.(5 marks)