Hydraulic Efficiency of Grate and Curb Inlets - Urban Drainage and ...

Table 4-1: Sample on-grade test data
Test ID
Number
Configuration
Longitudinal
Slope
(%)
Cross
Slope
(%)
Flow
Depth
(ft)
Prototype
Total
Flow
(cfs)
Efficiency
(%)
Top
Width
at
Control
(ft)
Top Width
Downstream
of Inlets
(ft)
56 Triple No. 13 0.5 1 0.333 4.4 82.1 15.8 9.0
57 Triple No. 13 0.5 1 0.501 20.6 43.2 18.2 18.2
58 Triple No. 13 0.5 1 0.999 126.6 22.7 18.2 18.2
59 Double No. 13 0.5 1 0.333 4.7 73.3 16.0 10.7
60 Double No. 13 0.5 1 0.501 22.6 35.9 18.2 18.2
61 Double No. 13 0.5 1 0.999 127.8 16.2 18.2 18.2
62 Single No. 13 0.5 1 0.333 4.8 61.3 16.0 15.8
63 Single No. 13 0.5 1 0.501 26.2 23.8 18.2 18.2
64 Single No. 13 0.5 1 0.999 126.4 9.9 18.2 18.2
For illustration purposes, trend lines are fitted to the on-grade test data (as second-order
polynomials) in Figure 4-1 through Figure 4-3. Each trend line illustrates how efficiency
increases with increasing inlet length. Velocity was chosen as the independent variable in these
figures because of its significant effect on inlet efficiency.
Figure 4-1: Type 13 combination-inlet on-grade test data
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