Sutro weirs consist of a rectangular section joined to a curved portion which provides proportionality for all heads above the rectangular section.
Figure 9 - Symmetrical Sutro Weir
For this type of weir, the curved portion is defined by the equation:
And the head-discharge relationship is:
Values of Cd for both symmetrical and non-symmetrical Sutro Weirs are summarized in the tables below.
|
Cd Values, Symmetrical |
|
a (ft) |
b, (ft) |
|
|
0.50 |
0.75 |
1.00 |
1.25 |
1.50 |
|
0.02 |
0.6080 |
0.6130 |
0.6170 |
0.6185 |
0.6190 |
|
0.05 |
0.6060 |
0.6110 |
0.6150 |
0.6170 |
0.6175 |
|
0.10 |
0.6030 |
0.6080 |
0.6120 |
0.6135 |
0.6140 |
|
0.15 |
0.6010 |
0.6055 |
0.6100 |
0.6115 |
0.6120 |
|
0.20 |
0.5990 |
0.6040 |
0.6080 |
0.6095 |
0.6100 |
|
0.25 |
0.5980 |
0.6025 |
0.6065 |
0.6080 |
0.6085 |
|
0.30 |
0.5970 |
0.0620 |
0.6060 |
0.6075 |
0.6080 |
|
Cd Values, Non-Symmetrical |
|
a (ft) |
b, (ft) |
|
|
0.50 |
0.75 |
1.00 |
1.25 |
1.50 |
|
0.02 |
0.6140 |
0.6190 |
0.6230 |
0.6245 |
0.6250 |
|
0.05 |
0.6120 |
0.6170 |
0.6210 |
0.6230 |
0.6235 |
|
0.10 |
0.6090 |
0.6140 |
0.6180 |
0.6195 |
0.6200 |
|
0.15 |
0.6070 |
0.6115 |
0.6160 |
0.6175 |
0.6180 |
|
0.20 |
0.6050 |
0.6100 |
0.6140 |
0.6155 |
0.6160 |
|
0.25 |
0.6040 |
0.6085 |
0.6125 |
0.6140 |
0.6145 |
|
0.30 |
0.6030 |
0.6080 |
0.6120 |
0.6135 |
0.6140 |
Table 14 - Values of Cd for Sutro Weirs
Note that when b > 1.5 or a>0.30 use Cd =0.6.