TEST1HYDRAULICSNOVEMBER2009-MARCH2010..doc

BEC 208 –HYDRAULICS AND HYDROLOGY TEST NO.1 INSTRUCTIONS : TIME: 2.5 HOURS Answer ALL questions. QUESTION 1 1a) Give a brief explanation on the following terms:- Uniform Flow Non-uniform Flow (8 marks) 1b) Distinguish the differences between flows in closed conduit and open channel. Give three (3) differences between those two types of flow. (6 marks) 1c) Define what is hydraulic structure and give three (3) examples of hydraulic structures. (5 marks) 1d) Briefly explain six (6) functions of hydraulic structures. (6 marks) QUESTION 2 2a) During a flood, water level in the channel below exceeded the bank full level of 3.0 m (Figure Q2 (a)). The flood bank is 12.0 m wide, located to the left of the main channel and it is grassed with side slope of 1V:3H. The estimated Manning’s coefficient, n for the bank in 0.035. The main channel has a roughness coefficient of 0.015 and a base width of 10.0 m, with a levee on its right at 1V:2H. The side slope, So for both main channel and flood bank is given as 0.001. Estimate the total discharge, QT for the compound channel. Figure Q2 (a) (15 marks) 2b) Calculate the discharge, Q, in the channel shown below (Figure Q2 (b)) given that the Manning’s roughness coefficient, n = 0.025. The depth of upstream of that channel, Y1 is 1.305m, the depth downstream, Y2 is 1.141m, and the distance between Y1 and Y2 is 10.0m apart. Figure Q2 (b) (10 marks) QUESTION 3 3a) The triangular channel in Figure Q3 is used to convey water at a rate of 15 m3/s. The Manning’s roughness coefficient, n for the channel is 0.012. During the field observation, the depth of upstream of that channel, Y1 is 1.305m, the depth downstream, Y2 is 1.265m, and the distance between Y1 and Y2 is 10.0m apart. Determine the depth, D of the channel. Calculate the Froude Number and determine whether the flow is subcritical or super-critical. Using the same discharge of 15 m3/s, com