Pipe head loss calculator (Darcy–Weisbach)
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Result
Head loss4.352 m
Velocity1.132 m/s
Reynolds number169765
Pressure drop (water)42.7 kPa
Step-by-step solution
Velocity
V = Q/A = 0.02/0.01767 = 1.132 m/s
Reynolds number
Re = VD/ν = 169765 (turbulent)
Darcy–Weisbach
hf = f·(L/D)·V²/(2g) = 0.02·(500/0.15)·1.132²/(2·9.81) = 4.352 m
Key formulas
- Reynolds number
- Re = V·D/ν = ρ·V·D/μ
- Flow regime
- laminar below Re ≈ 2000, turbulent above Re ≈ 4000
- Mean velocity
- V = Q/A, A = π·D²/4
- Darcy–Weisbach
- hf = f·(L/D)·V²/(2g)
- Minor losses
- hm = ΣK·V²/(2g)
- Typical K values
- entrance 0.5, exit 1.0, 90° bend ≈ 0.3
- Pressure drop
- Δp = ρ·g·hf
- Two open reservoirs
- Δz = (f·L/D + ΣK)·V²/(2g)
- Free outlet
- H = (1 + f·L/D + ΣK)·V²/(2g)
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