Head
(H)
(in.) |
Flow
in Gallons
(per min.) |
| 90°
notch |
60°
notch |
| 1/4 |
0.07 |
0.04 |
| 1/2 |
0.42 |
0.24 |
| 3/4 |
1.10 |
0.62 |
| 1 |
2.19 |
1.27 |
| |
3.83 |
2.21 |
| |
6.05 |
3.49 |
| |
8.89 |
5.13 |
| |
12.4 |
7.16 |
| |
16.7 |
9.62 |
| |
21.7 |
12.5 |
| |
27.5 |
15.9 |
|
|
34.2 |
19.7 |
| |
41.8 |
24.1 |
| |
50.3 |
29.0 |
| |
59.7 |
34.5 |
| |
70.2 |
40.5 |
| |
81.7 |
47.2 |
| |
94.2 |
54.4 |
| |
108 |
62.3 |
| |
123 |
70.8 |
| |
139 |
80.0 |
| |
156 |
59.9 |
| |
17 |
100 |
| |
193 |
112 |
| |
214 |
124 |
| |
236 |
136 |
| |
260 |
150 |
| |
284 |
164 |
|
 |
| Formula: |
Q = ( C ) ( 4/15
) ( L ) ( H ) |
 |
| Where: |
Q |
= |
flow of water in cu. ft.
per sec. |
| L |
= |
width of notch in ft.
at distance H above apex |
| H |
= |
head of water above apex
of notch in ft. |
| C |
= |
constant (varies w/ condition),
.57 used |
| a |
= |
no less than 3/4
L |
| |
for a 90° notch
the formula is |
| |
Q = 2.536 H 5/2 |
| |
for a 60° notch
the formula is |
| |
Q = 1.408 H 5/2 |
|
