Interactive Self-Study Module: Viscosity and Shear Stress

This module uses screencasts and interactive simulations to relate shear stress and velocity profiles. Screencasts are used to show how viscous fluids create shear stresses. An interactive simulation and example problems allow the user to test themselves. 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 two screencasts that introduce the idea of viscosity and relate shear stress to velocity profile and answer the question in the first screencast.  
  3. Use the interactive simulation to understand the effect shear stress has on velocity profiles.
  4. Try to solve the example problem before watching the solution in the screencast.
  5. Answer the ConcepTests.

A fluid is defined as a substance that deforms continuously when a shear stress is applied. An understanding of shear stress and velocity profiles is essential to fully comprehend what a fluid is. 

This module is intended for a fluid dynamics course.

Before studying this module, you should:

  • Be able to take simple derivatives.
  • Be able to explain what tangential forces are.
  • Know the difference between a force and a stress.

After studying this module, you should be able to:
  • Use the velocity profile to determine the shear stress.
  • Distinguish between Newtonian and non-Newtonian fluids.
  • Calculate the viscosity of a fluid knowing the shear stress.
  • Determine how changing tangential forces and viscosity affects velocity profiles.