Sewage Ditch Hydraulics
Rectangular sewer ditch, non-full flow, n=0.013. Velocity and capacity by Manning's equation.
| No. | Length L (m) | Area F (ha) | Spec. flow q | Through Q2 | Width B (m) | Height H (m) | Slope i (‰) | Fill h/D | Q1 (L/s) | Q3 (L/s) | KZ | Qs (L/s) | v (m/s) | Q (L/s) | ΔH (m) | Invert ↑ (m) | Invert ↓ (m) | ΔQ |
|---|
Max velocity
—
m/s
Min velocity
—
m/s
Design flow ΣQs
—
L/s
Capacity ΣQ
—
L/s
Average flow Q3 = Q1+Q2; variation KZ = 2.7/Q3^0.11; design flow Qs = Q3·KZ. Rectangular non-full velocity v = (B·o·H/(B+2·o·H))^(2/3)·√(i/1000)/n with n=0.013. Velocity ≥ 0.7 m/s is self-cleaning; capacity must be no less than design flow.