Object: To determine the coefficient of weir Cw for Broad-Crested weir.
Introduction to Practical
Apparatus Required:
- Perspex-sided tilting flume S-4; Model Broad-crested weir; stopwatch
Theory:
Weir:
Types of Weir:
Broad-crested weir and draw its sketch:
Why we provide Weir:
Procedure:
Make sure that the discharge apparatus is leveled, the broad crested weir is available and placed carefully and normally to the discharge apparatus, and note the breadth and height of the weir that are required for calculation.
Fill the discharge apparatus (Open Channel Place) with water until the water flows from the inlet tank to the discharge tank and flows over the broad crested weir.
- After the water surface is steady, read the water surface height over Wier and all water depth at another section by using a point gauge, which is the apparatus placed on the water surface to read the height of water.
- Then, write the times from the beginning of filling the discharge tank with water to the time that we want and note the volume collected between this short time to compute the actual discharge.
Reaped the procedure to calculate the discharge of different water quantities and its collected time.
Observations:
S. No. |
| t | Q | Y | hw | h w 𝑙 | Cw Q 128.8 h 3 / 2 w | |||
lit. | cc | s | cc/s | cm | cm | |||||
(5)= | (3) (4) | (8)= | (7) 31 | (9)= | ||||||
(1) | (2) | (3)= (2)x1000 | (4) | (6) | (7) | (5) 128.8x(7)3/2 | ||||
h w
Plot:Cw vs
𝑙
Cw
hw/ 𝑙
Fig. 1.1 Plot of Cw vs hw/ 𝑙
Results and comments: