Question

2. You are given a wide rectangular channel. The channel is a clean, straight, full stage, no rifts or deep pools (Hint uses Table 2.1 in HIRE to determine the Manning n). Given the following, Q = 1000 cfs, W = 100 feet, So = 2 ft/mile, calculate the following in English units. a. Calculate the normal depth. (Hint: check the formula in English units) b. Calculate the critical depth c. Calculate the minimum specific energy.

Answer 1

And Q = 1000 cfs - I Soz 2 ft/mile = 2/3280 2640 ac Walouft coefficrent n=0-03 mannings for clean straight full stage mennings equation 묵 Q= lug h AR so Area A = 100y P= Wetted perimeter = 100 + 2y R= Alp LODY 100tzy 늘 1.49 1000 Х looy [loca [00y 100+2y 1/3 [/2040 0:03 Solving above. go 4.196 Ft normal depth 2. critical depth Jc = (9 q=%w Je = ( (109100))"} 32.2 Je = 2.168 Ft © minimum specific energy Ec = ander **2-168 Ecmin =G= 3.252 ft