Object: To draw the specific energy curve for the open channel with subcritical and supercritical flow.
Apparatus Required:
- Perspex-sided Tilting flume S-4; stopwatch.
Perspex-sided S4 tilting flume
Theory:
Specific energy of a flowing liquid may be defined as its energy per unit weight (say per kg) with reference to datum passing through bottom of the channel.
Mathematically:
E = y + v2 / 2g
where
y = Depth of flow
v = Velocity of flow
Procedure:
Observations:
Width of flume, b = 7.9 cm
S. No | t | Q | q = Q b | Y0 | y1 | q v0  y0 | v1  q y1 | v2 0 1962 | v 2 1 2 g | E0   v2 y0 0 2g | E1   v2 y1 1 2g | ||
lit. | cm3 | s | cm3/s | cm2/s | cm | cm | cm/s | cm/s | cm | cm | cms | cm | |
(1) | (2) | (3) = (2)x 1000 | (4) | (5) = (3) (4) | (6) = (5) 7.9 | (7) | (8) | (6) (9) = (7) | (6) (10) = (8) | (9)2 (11)= 1962 | (10)2 (12)= 1962 | (13)= (7)+(11) | (14)= (8)+(12) |
Graphs:
Plot:- E0 against y0 E1 against y1
Results & Comments: