Inlet Design Coefficients
Coefficients for Inlet Control Design Equations
Unsubmerged | Submerged | |||||||
---|---|---|---|---|---|---|---|---|
Chart No. | Shape and Material | Nomograph Scale | Inlet edge description | FORM | K | M | C | Y |
1 | Circular Concrete | 1 | Square edge with headwall | 1 | 0.0098 | 2 | 0.0398 | 0.67 |
2 | Groove end with head wall | 1 | 0.0018 | 2 | 0.0292 | 0.74 | ||
3 | Groove end projecting | 1 | 0.0045 | 2 | 0.0317 | 0.69 | ||
2 | Circular CMP | 1 | Headwall | 1 | 0.0078 | 2 | 0.0379 | 0.69 |
2 | Mitered to slope | 1 | 0.021 | 1.33 | 0.0463 | 0.75 | ||
3 | Projecting | 1 | 0.034 | 1.5 | 0.0553 | 0.54 | ||
3 | Circular | A | Beveled ring, 45˚ bevels | 1 | 0.0018 | 2.5 | 0.0300 | 0.74 |
B | Beveled ring, 33.7˚ bevels | 1 | 0.0018 | 2.5 | 0.0243 | 0.83 | ||
8 | Rectangular Box | 1 | 30˚ to 75˚ wingwall flares | 1 | 0.026 | 1 | 0.0347 | 0.81 |
2 | 90˚ to 15˚ wingwall flares | 1 | 0.061 | 0.75 | 0.0400 | 0.8 | ||
3 | 0˚ wingwall flares | 1 | 0.061 | 0.75 | 0.0423 | 0.82 | ||
9 | Rectangular Box | 1 | 45˚ Wingwall flare, d=.0430 | 2 | 0.51 | 0.667 | 0.0309 | 0.80 |
2 | 18˚-33.7˚ wingwall flare, d=.0830 | 2 | 0.486 | 0.667 | 0.0249 | 0.83 | ||
10 | Rectangular Box | 1 | 90˚ headwall with chamfers | 2 | 0.515 | 0.667 | 0.0375 | 0.79 |
2 | 90˚ headwall with 45˚ bevels | 2 | 0.495 | 0.667 | 0.0314 | 0.82 | ||
3 | 90˚ headwall with 33.7˚ bevels | 2 | 0.486 | 0.667 | 0.0252 | 0.865 | ||
11 | Rectangular Box | 1 | chamfers; 45˚ skewed headwall | 2 | 0.545 | 0.667 | 0.0505 | 0.73 |
2 | chamfers; 30˚ skewed headwall | 2 | 0.533 | 0.667 | 0.0425 | 0.705 | ||
3 | chamfers; 15˚ skewed headwall | 2 | 0.522 | 0.667 | 0.0402 | 0.68 | ||
4 | 45˚ bevels; skewed headwall | 2 | 0.498 | 0.667 | 0.0327 | 0.75 | ||
12 | Rectangular Box - Chamfers | 1 | 45˚ non-offset wingwall flares | 2 | 0.497 | 0.667 | 0.0339 | 0.803 |
2 | 18.4˚ non-offset wingwall flares | 2 | 0.493 | 0.667 | 0.0361 | 0.806 | ||
3 | 18.4˚ non-offset wingwall flares, 30˚ skewed barrel | 2 | 0.495 | 0.667 | 0.0386 | 0.71 | ||
13 | Rectangular Box - Top Bevels | 1 | 45˚ wingwall flares - offset | 2 | 0.497 | 0.667 | 0.0302 | 0.835 |
2 | 33.7˚ wingwall flares - offset | 2 | 0.495 | 0.667 | 0.0252 | 0.881 | ||
3 | 18.4˚ wingwall flares - offset | 2 | 0.493 | 0.667 | 0.0227 | 0.887 | ||
16-19 | C M Boxes | 2 | 90˚ headwall | 1 | 0.0083 | 2 | 0.0379 | 0.69 |
3 | Thick wall projecting | 1 | 0.0145 | 1.75 | 0.0419 | 0.64 | ||
5 | Thin wall projecting | 1 | 0.034 | 1.5 | 0.0496 | 0.57 | ||
29 | Horizontal Ellipse - Concrete | 1 | Square edge with headwall | 1 | 0.01 | 2 | 0.0398 | 0.67 |
2 | Groove end with head wall | 1 | 0.0018 | 2.5 | 0.0292 | 0.74 | ||
3 | Groove end projecting | 1 | 0.0045 | 2 | 0.0317 | 0.69 | ||
30 | Vertical Ellipse - Concrete | 1 | Square edge with headwall | 1 | 0.01 | 2 | 0.0398 | 0.67 |
2 | Groove end with head wall | 1 | 0.0018 | 2.5 | 0.0292 | 0.74 | ||
3 | Groove end projecting | 1 | 0.0095 | 2 | 0.0317 | 0.69 | ||
34 | Pipe Arch 18" Corner Radius CM | 1 | 90˚ headwall | 1 | 0.0083 | 2 | 0.0379 | 0.69 |
2 | Mitered to slope | 1 | 0.03 | 1 | 0.0463 | 0.75 | ||
3 | Projecting | 1 | 0.034 | 1.5 | 0.0496 | 0.57 | ||
35 | Pipe Arch 18" Corner Radius CM | 1 | Projecting | 1 | 0.0300 | 1.5 | 0.0496 | 0.57 |
2 | No Bevels | 1 | 0.0088 | 2 | 0.0368 | 0.68 | ||
3 | 33.7˚ bevels | 1 | 0.003 | 2 | 0.0269 | 0.77 | ||
36 | Pipe Arch 31" Corner Radius CM | 1 | Projecting | 1 | 0.0300 | 1.5 | 0.0496 | 0.57 |
2 | No Bevels | 1 | 0.0088 | 2 | 0.0368 | 0.68 | ||
3 | 33.7˚ bevels | 1 | 0.003 | 2 | 0.0269 | 0.77 | ||
40-42 | Arch CM | 1 | 90˚ headwall | 1 | 0.0083 | 2 | 0.0379 | 0.69 |
2 | Mitered to slope | 1 | 0.03 | 1 | 0.0463 | 0.75 | ||
3 | Thin wall projecting | 1 | 0.034 | 1.5 | 0.0496 | 0.57 | ||
55 | Circular | 1 | Smooth tapered inlet throat | 2 | 0.534 | 0.555 | 0.0196 | 0.90 |
2 | Rough tapered inlet throat | 2 | 0.519 | 0.64 | 0.0210 | 0.90 | ||
56 | Elliptical Inlet Face | 1 | Tapered inlet - beveled edges | 2 | 0.536 | 0.622 | 0.0368 | 0.83 |
2 | Tapered inlet - square edges | 2 | 0.5035 | 0.719 | 0.0478 | 0.8 | ||
3 | Tapered inlet - thin edge projecting | 2 | 0.547 | 0.8 | 0.0598 | 0.75 | ||
57 | Rectangular | 1 | Tapered inlet throat | 2 | 0.475 | 0.667 | 0.0179 | 0.97 |
58 | Rectangular Concrete | 1 | Side tapered - less favorable edges | 2 | 0.56 | 0.667 | 0.0466 | 0.85 |
2 | Side tapered - more favorable edges | 2 | 0.56 | 0.667 | 0.0378 | 0.87 | ||
59 | Rectangular Concrete | 1 | Slope tapered - less favorable edges | 2 | 0.5 | 0.667 | 0.0466 | 0.65 |
2 | Slope tapered - more favorable edges | 2 | 0.5 | 0.667 | 0.0378 | 0.71 |