Test Papers / Previous Question Papers of Indira Gandhi National Open University ET533B Open Channel Flow June 2007

B.Tech. Civil (Water Resource Engineering)

Term-End Examination

ET-533(B) Open Channel Flow

Time: 3 hours
Maximum Marks: 70

Note: Solve any five questions. All questions carry equal marks. Give neat and labelled sketches in support of your answer. Use of calculator is permitted.

June 2007

1. (a) A triangular section with side slope z= 1.5 runs water at a depth of 3.5 m. Calculate its hydraulic radius (R), and top width (T). (5)

(b) Distinguish between hydraulic radius and hydraulic depth of an open channel.

(c) If a triangular section has a section factor (z) = 9.2 in metric units, find the depth of flow in it if z=2. 5

2. (a) Explain what you understand by specific energy; and give a typical specific-energy curve for a given discharge in an open channel. 6

(b) A rectangular channel expands smoothly from a widtn of 2 m to 3.5 m. If u/s of the expansion has a depth of flow as 0.75 m, and the velocity of flow is 2.3 m/s, derive the equation in terms of y (d/s flow depth) to help estimate the depth of flow after the expansion. (There is no change in the elevation of the channel bed). Indicate how you will solve this equation; and which value of y would you adopt out of the values that form the solution of the equation. 8

3. (a) Explain how bed slopes are categorised as hoiizontal, mild, critical, and steep 4

(b) Derive, from first principles, an expression for the hydraulic exponent for a uniform-flow computation in terms of flow depth, flow area, top flow width, hydraulic radius, and (dP)/dy. 7

(c) If the hydraulic exponent computation M=3.1.2, and hydraulic exponent for uniform flow computation, N=3.71, find the value of J.

4. (a) Discuss, in brief, the design of channel contradictions and expansions at transitions. 5

(b) A venturi flume is 1.5 m wide at its entrance, and 0.5 m at its throat. Neglecting hydraulic losses in the flume, determine the flow through the flume, if the depth of flow at these sections is 0.6 m and 0.55 m, respectively. 9

5. Show that for negative surges, in an open channel: V_w=3root(gy)-V₂ - 2root(gy₂), symbols denoting their usual meaning. (14)

6. Starting from velocity potential φ, discuss mathematically the particle velocity and orbital motion with respect to a wave in an open channel. (14)

7. Write short notes on any two of the following : 2x7

(i) Velocity distribution in open channels with triangular, trapezoidal, horrow rectangular and circular cross-sectional shapes

(ii) Wave action on dams

(iii) Wave action on structures standing on shores

The following is a partial list of Testpapers of similar / related courses to Open Channel Flow offered by Indira Gandhi National Open University

• ET502B Structural Analysis
• ET301A / ET534B System Methods
• ET534 (C) Water Resources Planning
• ET540B Flow in Open Channel

Distance Education Universities
(by University name)

Distance Education Colleges
(by State name)

Indira Gandhi National Open University (IGNOU)

Annamalai University - Directorate of Distance Education

Institute of Distance Education - University of Madras

Mahatma Gandhi University - School of Distance Education

Achaya Nagarjuna University Center for Distance Education