Question

Find the discharge through a rectangular orifice 3.2 m wide and 1.7 m deep fitted to a easier tank. The water level in a team is 3.3 m above the top edge of orifice. Take Cd = 0.6

(a) 29.4 m^3/s

(b) 58.5 m^3/s

(c) 67.9 m^3/s

(d) 78.7 m^3/s

I have been asked this question by my school principal while I was bunking the class.

This intriguing question comes from Flow through Large Orifice topic in section Orifices, Mouthpieces, Notches and Weirs of Fluid Mechanics

Answer 1

Right answer is (a) 29.4 m^3/s

The best I can explain: Q = 2/3 Cd *b*√2g* (H2^1.5 – H1^1.5)

                       Here,

                       H1 = 5

                       H2 = 3.3

                       b = 3.2

Hence, Q = 29.4 m^3/s.