P.T.U BTech Civil Engineeing (Semester 4 ) Fluid Mechanics (CE-204)

B.Tech (Semester 4th)
Civil Engineering
Fluid Mechanics 2
(CE-204)

(Section A)
(2X10=20)

Q1)

a) Define Displacement thickness. Give its importance.

b) write down the Navier-Stroke equations in cartesian coordinates for two dimensional flow.

c) Define Magnus effect and its importance.

d) Define critical depth and flow in channel.

e) define steep slope channels.

f) What is hydraulic jump?

g) Define Darcy's law with its assumptions.

h) Differentiate between specific force and specific energy.

i) differentiate between uniform flow and non-uniform flow.

j) what do you understand by the term separation of flow?

(Section- B)

(4X5=20)

Attempt any four questions from Section B

Q2) A fluid of relative density 0.92 and dynamic viscosity 1.05 poise flows between two parallel plates kept at a distance of 1.5 cm apart. if the mean velocity is 1.5m/s calculate (a) the maximum velocity (b) Velocity at a distance of 0.5 cm from one of the plates (c) head loss in a distance of 25m.

Q3) A flat plate of 2.0 m width and 40 m length is kept parallel to air flowing at 5.0 m/sec velocity at 15 degrees celcius. determine the length over whichthe boundary layer is laminar. shear at the location when boundary layer ceaser to be laminar.

Q4) Draw a neat sketch of velocity distribution near a hydrodynamically smooth surface indicationg clearly the velocity distributior to transition region. give equations for velocity distribution in each region.

Q5) A circular cylinder of 2 m diameter and 12 m length is rotated at 300 rpm about its axis when it is kept in an air stream of 40 m/s velocity and with its axis perpendicular to the flow. Determine (a) circulation around the cylinder. (b) position of stagnations points and (c) resultant force on the cylinder. Take Cd=0.52.

Q6) Explain the significance of channels of most efficient section. Derive their conditions for a rectangular open channel.

(Section C)

(2X10=20)

Attempt any Two questions from Section C

Q7) (a) In a rectangular channel 2.5m wide laid at a slope of 0.0036, uniform flow occurs at a depth of 2m. findhow highcanahumpcanbe raised on the channel bed without causing a change in the U/S depth. If the U/S depth is to be raised to 2.4m, what should be the height of the hump? Assume Manning's N=0.015.

(b) Discuss the typical velocity destribution in an open channel.

Q8) (a) Deriver the expression for energy loss by hydraulic jump in a rectangular channel.

(b) Water flows over the slipway of a dam at a depth of 2.73 m over it. the difference of elevation between spillway crest and down stream bed level is 30m. Ifthe dischargecoefficient of spillway is 0.75, determine the water depth after the jump and the head loss in the jump.

Q9) (a) A rectangular channel 10m wide carries a discharge of 30 meter cube/s. It is laid at a slope of 0.0001. If at a section in this channel the depth is 1.6m, how far from the section will the depth of flow be 2.0m? Take Manning's N=0.015.

(b) Discuss the characterstics of surface profiles formed in mild slope and steep slope channels.