Sewage Pipe Hydraulics (Ⅱ)
Circular sewer, non-full flow, n=0.014, filling ratio h<D/2. θ = acos(1 − 2h/D).
| No. | Length L (m) | Area F (ha) | Spec. flow q | Through Q2 | Dia. D (m) | Slope i (‰) | Fill h/D | Q1 (L/s) | Q3 (L/s) | KZ | Qs (L/s) | θ (°) | v (m/s) | Q (L/s) | ΔH (m) | Invert ↑ (m) | Invert ↓ (m) | ΔQ |
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Max velocity
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m/s
Min velocity
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m/s
Design flow ΣQs
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L/s
Capacity ΣQ
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L/s
Average flow Q3 = Q1+Q2 (Q1 = F·q); variation KZ = 2.7/Q3^0.11; design flow Qs = Q3·KZ. Non-full circular velocity by Manning n=0.014; θ = acos(1−2h/D). Velocity ≥ 0.7 m/s is self-cleaning; capacity must be no less than design flow.