Lesson 1.2c Definition of Viscosity

Goals You can:

  1. Explain the meaning of stress, shear stress, normal stress, rate-of-shear-strain, velocity gradient
  2. Explain the meaning of a Newtonian Fluid and a Non-Newtonian Fluid. Give examples of fluids in each of these categories.
  3. Relate shear stress and velocity gradient using the definition of viscosity (Eq. 1)
(1)
\begin{align} \tau =\mu \frac{dV}{dy} \end{align}

Rationale

  • Shear stress (i.e. viscous stress) causes head loss, pressure drop, drag, energy loss etc. It is of paramount importance in many practical applications.

Resouces

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License