Pipe friction & head loss worksheet with answers

Free printable Pipe friction & head loss worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
V = 0.5 m/sD = 50 mmρ = 880 kg/m³, μ = 0.04 Pa·s

Hydraulic oil (ρ = 880 kg/m³, μ = 0.04 Pa·s) flows at 0.5 m/s through a pipe with an inside diameter of 50 mm. Find the Reynolds number Re.

ρ = 880 kg/m³μ = 0.04 Pa·sV = 0.5 m/sD = 50 mm
Re =
2.Easy
V = 1.6 m/sD = 150 mmν = 1.31 × 10⁻⁶ m²/s

Water at 10 °C (ν = 1.31 × 10⁻⁶ m²/s) flows at a mean velocity of 1.6 m/s through a pipe with an inside diameter of 150 mm. Find the Reynolds number Re.

V = 1.6 m/sD = 150 mmν = 1.31 × 10⁻⁶ m²/s
Re =
3.Medium
V = 2.1 m/sD = 50 mmL = 50 mf = 0.02

Water flows at a mean velocity of 2.1 m/s through a pipe 50 m long with an inside diameter of 50 mm. Use the Darcy friction factor f = 0.02 and g = 9.81 m/s². Find the friction head loss hf.

V = 2.1 m/sL = 50 mD = 50 mmf = 0.02g = 9.81 m/s²
hf = m
4.Medium
Q = 3 L/sD = 50 mmL = 100 mf = 0.022

Water flows at 3 L/s through a pipe 100 m long with an inside diameter of 50 mm. Use the Darcy friction factor f = 0.022 and g = 9.81 m/s². Find the friction head loss hf.

Q = 3 L/sL = 100 mD = 50 mmf = 0.022g = 9.81 m/s²
hf = m
5.Hard
K = 10free outletH = ?L = 200 m, D = 200 mm, f = 0.0182× bend (K = 0.3)

A pipe 200 m long with an inside diameter of 200 mm (Darcy friction factor f = 0.018) 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), 2 bends (K = 0.3 each) and a valve (K = 10). Use g = 9.81 m/s². How far H must the reservoir surface be above the pipe outlet for a flow rate of 40 L/s?

Q = 40 L/sL = 200 mD = 200 mmf = 0.018Kentrance = 0.5Kbend = 0.3 (×2)Kvalve = 10
H = m
6.Hard
K = 0.2Δz = ?L = 100 m, D = 200 mm, f = 0.0152× bend (K = 0.3)

Two open reservoirs are joined by a pipe 100 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.015. 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 40 L/s?

Q = 40 L/sL = 100 mD = 200 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×2)Kvalve = 0.2Kexit = 1.0
Δz = m

Answer key

  1. 1. Re = 550
  2. 2. Re = 183206
  3. 3. hf = 4.495 m
  4. 4. hf = 5.235 m
  5. 5. H = 2.487 m
  6. 6. Δz = 0.8097 m

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