CE6451 Fluid Mechanics and Machinery
Second year, Department of Aeronautical Engineering
First and second Units Questions.
Answer ALL Questions        PART- A  [10 Marks]
  1. Define Newton’s law of viscosity?
  2. Define specific weight?
  3. What is meant by stagnation pressure?
  4. Differentiate between dynamic viscosity and kinematic viscosity?
  5. What is venturimeter? and explain its basic principles?
  6. What are energy lines and hydraulic gradient lines?
  7. What is meant by laminar boundary layer?
  8. Define energy thickness?
  9. What is the use of moody’s diagram?
  10. What do you mean by flow through parallel pipes?
Answer ALL Questions         PART - B [65 Marks]
1.       a) Calculate the specific weight. Mass density, specific gravity and specific volume of oil having a volume of 4.5m3and weight 40KN.                                                                                      (3)
      b) Two large plane surface of 2.5cm a part. The space between the surfaces is filled with   glycerin.     What force is required to trag a very thin plate of surface area 0.5m2 between the two   large surfaces at a speed of 0.6m/s. If
                                                          i.            The thin plate is in the middle of two plane surfaces.
                                                        ii.            The thin plate is such a distance of 0.8cm from one of the surfaces
   Take the dynamic viscosity of glycerin 8.1×10-1 N s/m2.                                                        (10)
2.      a) Calculate the capillary effect in mm glass of tube of 4mm diameter when immersed in i) Water,   ii) Mercury. The temperature of liquid is 200c and the value of the surface tension of water is 0.073575 N/m and the surface tension of mercury is 0.51 N/m respectively. The angle of contact for water is 00 and the angle of contact for mercury is 1300 Take the density of water at 200c= 998 kg/m3 .The specific gravity of mercury is 13.6.                                            (8)
b) A simple U tube manometer containing mercury connected to a pipe in which a fluid of specific gravity 0.8 and having vacuum pressure is flowing. The other ends of the manometer open to the atmosphere. Find the vacuum pressure of the pipe. If the difference of the mercury level in the two limb 40cm the high of the fluid in the left limb from the centre of the pipe is 15cm below.                                                                                                                                 (5)
3.      a) i) Water flows through a pipe AB 1.2m diameter at 3m/s and then passes through a pipe BC 1.5m diameter at C the pipe branches into CD in 0.8m diameter and carries 1/3 of the flow in AB the flow velocity in branch CE is 2.5 m/s .Find the volume rate of flow in AB , velocity in BC, the velocity in CD and the diameter of CE.                                                                 (8)
ii) The water is flowing through a pipe having diameter 20cm and 10cm at section 1 and 2 respectively .The rate of flow through a pipe is 35 litre/sec . The section one is 6m above datum and section 2 is 4m above datum. If the pressure of section 1 is 39.24 N/cm2. Find the intensity of pressure at section 2.                                                                                                 (5)
4.      a) A smooth pipe of diameter 80mm and 800m long carries water at the rate of 0.480 m3/min. Calculate the loss of head valve shearing stress and centre line velocity take kinematic viscosity of water as 0.015 stroke the value of coefficient of friction from the relation given as F=0.0791/(Re)1/4.                                                                                                                   (8)
b) An horizontal venturimeter consist of 30cm diameter at inlet section and 15cm diameter and throat section the reading of differential manometer connected to the inlet and throat is 20cm of mercury. Determine the rate of flow.                                                                                       (5)
5.      The difference  in water surface level in two tanks which are connected by three pipe in serious of length 300mm, 170m and 210m and of diameter 300mm,200mm and 400mm respectively is 12m .Determine the rate of flow of water if coefficient of friction are 0.005, 0.0052,0.0048 respectively.1)Considering minor loss, 2) Neglecting minor loss.                                       (13)
PART - C [15 Marks]
6.      a) Derive the continuity equation of differential form.                                                               (5)
b) Derive the Euler’s equation of motion and deduce the expression to Bernoulli’s equation.            (10)