Question

A long rectangular concrete channel (b = 10 ft, n = 0.015) carries 400 cfs. There is a grade break in the channel; the slope upstream of the grade break is 0.02 and the slope downstream of the grade break is 0.002. The following equations are valid for a rectangular channel:

• DC = [(Q2)/(g*b2)]1/3

• y2 = 0.5*y1*[(1+8NFr12)1/2 -1] (for hydraulic jump)

• NFr = v/(g*y)1/2

• a) Use calculations to classify each section of the channel (steep, mild, horizontal, adverse or critical) and show that a hydraulic jump can occur

• b) Show with calculations whether the hydraulic jump will occur upstream of the grade break, at the grade break or downstream of the grade break, and sketch channel profile

• c) Estimate energy lost in the hydraulic jump

Please show all work. Thank you so much in advance!

Answer 1