Hydraulic Efficiency of Grate and Curb Inlets - Urban Drainage and ...
Hydraulic Efficiency of Grate and Curb Inlets - Urban Drainage and ...
Hydraulic Efficiency of Grate and Curb Inlets - Urban Drainage and ...
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Table 5-2: Empirical equations for grate <strong>and</strong> curb inlets<br />
Inlet Predictive Equation Simplified Form<br />
Type 13<br />
Combination<br />
0.665 2<br />
0.835<br />
2<br />
−1.138<br />
0.665 0.835 −0.606<br />
⎛ ⎞ ⎛V<br />
T ⎞ ⎛V<br />
⎞<br />
E = 0.063 ⎜ ⎟ ⎜ ⎟ E =<br />
−0.473<br />
0.835 −0.<br />
303<br />
⎜<br />
⎝<br />
h<br />
L<br />
⎟<br />
⎠<br />
⎜<br />
⎝<br />
gA ⎟<br />
⎠<br />
⎜ ⎟<br />
⎝ gL ⎠<br />
h<br />
L<br />
T<br />
A<br />
V<br />
g<br />
Equation<br />
5-8<br />
R 2 Average efficiency error (%) Maximum efficiency error (%)<br />
0.895 4.7 22.6<br />
Type 16<br />
Combination<br />
0.573 2<br />
0.756<br />
2<br />
−0.920<br />
0.573 0.756 −0.328<br />
⎛ ⎞ ⎛V<br />
T ⎞ ⎛V<br />
⎞<br />
E = 0.095 ⎜ ⎟ ⎜ ⎟ E =<br />
−0.347<br />
0.756 −0.<br />
164<br />
⎜<br />
⎝<br />
h<br />
L<br />
⎟<br />
⎠<br />
⎜<br />
⎝<br />
gA ⎟<br />
⎠<br />
⎜ ⎟<br />
⎝ gL ⎠<br />
h<br />
L<br />
T<br />
A<br />
V<br />
g<br />
Equation<br />
5-9<br />
R 2 Average efficiency error (%) Maximum efficiency error (%)<br />
0.844 5.1 21.9<br />
Type<br />
R <strong>Curb</strong><br />
E<br />
2<br />
0.545<br />
2<br />
−0.879<br />
−0.328<br />
0.231<br />
⎛V<br />
⎞ ⎛V<br />
⎞<br />
c<br />
= 0.076⎜<br />
⎟ ⎜ ⎟ Sc E =<br />
−0.879<br />
0.545 −0.<br />
334<br />
⎜ gh ⎟<br />
⎝ ⎠<br />
⎜ gL ⎟<br />
⎝ ⎠<br />
( ) 0. 231<br />
L<br />
V<br />
h<br />
S<br />
g<br />
Equation<br />
5-10<br />
R 2 Average efficiency error (%) Maximum efficiency error (%)<br />
0.890 5.1 29.1<br />
Observed<br />
1<br />
0.9<br />
0.8<br />
0.7<br />
0.6<br />
0.5<br />
0.4<br />
0.3<br />
0.2<br />
0.1<br />
0<br />
1<br />
1 ft depth<br />
0.5 ft depth<br />
0.33 ft depth<br />
Equal<br />
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1<br />
Predicted<br />
Figure 5-8: Predicted vs. observed efficiency for Type 13 combination-inlet from empirical equation<br />
65