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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
V = 1.5 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 1.5 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 = 1.5 m/sD = 50 mm
Re =
2.Easy
Q = 6 L/sD = 50 mmν = 1.14 × 10⁻⁶ m²/s

Water at 15 °C (ν = 1.14 × 10⁻⁶ m²/s) flows through a pipe with an inside diameter of 50 mm at 6 L/s. Find the Reynolds number Re.

Q = 6 L/sD = 50 mmν = 1.14 × 10⁻⁶ m²/s
Re =
3.Medium
V = 1.6 m/sD = 50 mmL = 400 mf = 0.028

Water flows at a mean velocity of 1.6 m/s through a pipe 400 m long with an inside diameter of 50 mm. Use the Darcy friction factor f = 0.028 and g = 9.81 m/s². Find the friction head loss hf.

V = 1.6 m/sL = 400 mD = 50 mmf = 0.028g = 9.81 m/s²
hf = m
4.Medium
V = 1.9 m/sD = 50 mmL = 800 mf = 0.025

Water flows at a mean velocity of 1.9 m/s through a pipe 800 m long with an inside diameter of 50 mm. Use the Darcy friction factor f = 0.025 and g = 9.81 m/s². Find the friction head loss hf.

V = 1.9 m/sL = 800 mD = 50 mmf = 0.025g = 9.81 m/s²
hf = m
5.Hard
K = 5free outletH = ?L = 100 m, D = 300 mm, f = 0.024× bend (K = 0.3)

A pipe 100 m long with an inside diameter of 300 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), 4 bends (K = 0.3 each) and a valve (K = 5). Use g = 9.81 m/s². How far H must the reservoir surface be above the pipe outlet for a flow rate of 75 L/s?

Q = 75 L/sL = 100 mD = 300 mmf = 0.02Kentrance = 0.5Kbend = 0.3 (×4)Kvalve = 5
H = m
6.Hard
K = 10Δz = ?L = 100 m, D = 100 mm, f = 0.0152× bend (K = 0.3)

Two open reservoirs are joined by a pipe 100 m long with an inside diameter of 100 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 = 10) 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 20 L/s?

Q = 20 L/sL = 100 mD = 100 mmf = 0.015Kentrance = 0.5Kbend = 0.3 (×2)Kvalve = 10Kexit = 1.0
Δz = m

Answer key

  1. 1. Re = 1650
  2. 2. Re = 134025
  3. 3. hf = 29.23 m
  4. 4. hf = 73.6 m
  5. 5. H = 0.8244 m
  6. 6. Δz = 8.957 m

Full step-by-step solutions: practise this topic on examproblems.com.