Object: To find the coefficient of discharge for a small orifice.
Apparatus Required:
- Hydraulic Bench with orifice (and notch) apparatus, measuring cylinder, stopwatch, and Vernier calipers.

Flow under constant head
Theory:
Flow under constant head:
- Q = Cd A
2 g H
- where Q = Discharge m3 / sec
- A = Orifice x – sec are a m2
- g = Acceleration due to gravity 9.81 m/sec2
- H = Head over orifice centre m
Cd =Q/ (A)(4.1)
2 g H
Procedure:
Observations:
Area of tank, At.. x ..= .. cm2
Area of orifice, A
()2= .. cm2
4
- Flow under Constant Head
S. No. | H (cm) | V (cm3) | T (Sec) | Qac = V/T (cm3 /sec) | H cm | Cd = Qac / Qth =Qac A2gH |
1 2 3 4 | Mean | |||||
……….. |

Results & Comments: