Question

Find the discharge through totally drowned orifice of width 3.3 m if the difference of water levels on both side of the orifice be 50 cm. The height of water from to and bottom of the orifice are 2.25 m and 2.67 m respectively.

(a) 2.8 m^3/s

(b) 2.7 m^3/s

(c) 2.6 m^3/s

(d) 2.5 m^3/s

I have been asked this question in an interview.

Enquiry is from Flow through Large Orifice topic in division Orifices, Mouthpieces, Notches and Weirs of Fluid Mechanics

Answer 1

Correct option is (a) 2.8 m^3/s

For explanation: Q = Cd * b * (H2 – H1) √2gH

                    Here, b = 3.3

                             H2 = 2.67

                             H1 = 2.25

                             H = 50

                     Q = 2.6 m^3/s.