impeller.net The Online Pump Magazine

22.09.2003

Newtonian Fluid

A fluid is classified as being Newtonian if it conforms to NEWTON’s friction law, i.e. if viscosity remains constant with agitation or varying shear rate (i.e. viscosity is only affected by temperature changes) and its shear rate being proportional to the velocity gradient vertical to the direction of flow.

It is, on one-dimensional flow:, physically defined as:












Of Newtonian fluid characteristics are e.g. the following:

  • water
  • oils
  • gases
  • mercury
  • alcohol
  • petrol

If it is not known whether a fluid is of Newtonian flow characteristics or not, it should be laboratory-tested.



Also see:
{Duty Conversion Of High-Viscous Fluids}{Non-Newtonian fluids}
{Viscosity}