FLUID MECHANICS PAPER 2

DOWNLOAD MECHANICAL ENGINEERING PREVIOUS YEARS QUESTION PAPERS B.TECH PTU

FLUID MECHANICS ME 206 B. Tech 4th Sem May 2k5

Max Marks 60

Note: Section A is compulsory. Attempt any Four questions from Section B and two from Section C

Section A Marks 2 each
1.

• Define and distinguish between uniform and nonuniform flow.
• Define stream line, streak line, stream tube, path line.
• Write the momentum equation for compressible fluids in ‘x’ direction.
• Explain Turbulent Flow, Laminar Flow.
• Which of the following functions represents possible irrotational flow?

(i) y = A(x2 - y2)
(ii) y = A sin (px/l) + B sin (py/l) where A, B and l are constants.

• What is Normal Shock and how is it obtained?
• Find the Kinematic Viscosity in stokes of a liquid where specific gravity is 0.95 and Viscosity is 0.11 poise.
• Explain displacement thickness and momentum thickness.
• What is difference between friction drag and pressure drag?
• What is Mach number and its importance?

Section B Marks 5 each

2. Derive a stream function for a flow to a line source of strength m2/s per meter.

3. Show that for Laminar flow, the point of maximum instability exists at a distance 2/3rd of pipe radius.

4. A source with strength of 0.26 m2/s and a vortex with a strength of 1 m2/s (anticlockwise) are located at origin. Determine the equation for stream function and velocity potential.

5. What size pipe should be installed to carry 5.5 x 10-3 m2/s oil with Kinematic Viscosity v = 6 x 10-6 m2/s under laminar flow conditions.

6. What is drag coefficient? Discuss its importance and on what factors does it depend.

Section C Marks 10 each

7. Show that discharge per unit width between two parallel plates at a distance ‘b’ apart, when one plate is moving at velocity V while other held stationary for the condition of zero stress at a fixed plate is Q = b V /3.

8. (a) Determine Tube Air speed, stagnation temp. and density at the nose of pitot tube comprising the speed indicator.
(b) A rotational mixing device is constructed with two circular discs each 10 cm in diameter. These discs are spaced 1.2 m apart on the two ends of a horizontal rod whose centre has a vertical shaft attached to it. Estimate the power required for rotating when this mixer turns 60 revolutions per minute having following fluid properties:

r = 960 kg/ m3, m = 0.08075 kg-m/s for 3000< Re < 5000 and Cd = 1.2

9. (a) An aeroplane weighing 50 kN is flying in a horizontal direction at 360 km/hr. The plane spans 15 m and has a wing surface are of 35 m2. Determine the Lift coefficient and power required to drive the plane. Assume drag coefficient Cd = 0.03, r = 1.2 kg/ m3 for air.
(b) Explain the Isotropic and homogeneous turbulence.