Water at 10 °C (ν = 1.31 × 10⁻⁶ m²/s) flows at a mean velocity of 1 m/s through a pipe with an inside diameter of 40 mm. Find the Reynolds number Re.
Pipe friction & head loss worksheet with answers
Water at 20 °C (ν = 1.00 × 10⁻⁶ m²/s) flows at a mean velocity of 2.5 m/s through a pipe with an inside diameter of 100 mm. Find the Reynolds number Re.
Water flows at 75 L/s through a pipe 300 m long with an inside diameter of 250 mm. Use the Darcy friction factor f = 0.022 and g = 9.81 m/s². Find the friction head loss hf.
Water flows at 5 L/s through a pipe 1000 m long with an inside diameter of 100 mm. Use the Darcy friction factor f = 0.03 and g = 9.81 m/s². Find the friction head loss hf.
Two open reservoirs are joined by a pipe 150 m long with an inside diameter of 300 mm and a Darcy friction factor f = 0.018. The minor losses are a square-edged entrance (K = 0.5), 2 bends (K = 0.3 each), a valve (K = 0.2) and the exit into the lower reservoir (K = 1.0). Use g = 9.81 m/s². What difference in water level Δz between the reservoirs gives a flow rate of 150 L/s?
A pipe 200 m long with an inside diameter of 200 mm (Darcy friction factor f = 0.02) runs from an open reservoir and discharges as a free jet into the air. The minor losses are a square-edged entrance (K = 0.5), 3 bends (K = 0.3 each) and a valve (K = 2). Use g = 9.81 m/s². How far H must the reservoir surface be above the pipe outlet for a flow rate of 50 L/s?
Answer key
- 1. Re = 30534
- 2. Re = 250000
- 3. hf = 3.141 m
- 4. hf = 6.197 m
- 5. Δz = 2.594 m
- 6. H = 3.15 m
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