Interactive Self-Study Module: Calculating the Diameter in Pipe Flow


This module uses screencasts to teach students how to calculate the diameter of a pipe with viscous flow. Your retention of material in this module will increase if you write down reasons for your answers to ConcepTests, questions in screencasts, and you try to solve the example problem before watching the solution in the screencast.  We suggest using the learning resources in the following order:

  1. Attempt to answer the multiple choice ConcepTest and solve the example problem before watching the screencasts or working with the simulations.
  2. Watch the screencast that provides the basics on how to calculate the diameter.
  3. Try to solve the example problem before watching the solutions in the example screencast.
  4.  Answer the ConcepTests.
  5. Look at the list of key points, but only after you try to list the key points yourself.
  • Calculating the diameter of a pipe is often an important part of designing a system but can be tricky to do.
  • This module is intended for fluid mechanics courses.
Before studying this module, you need to:
  • Be able to use the Moody chart.
  • Grasp the concept of the Reynolds number (Re) and be able to calculate it.
  • Know what head loss is and how to calculate it.
  • Understand and know how to simplify the energy equation.
After studying this module, you should be able to:
  • Rewrite the important equations in terms of diameter.
  • Solve for the friction factor using both trial-and-error and Excel.
  • Use the friction factor and the simplified energy equation to calculate the diameter.