2016 Apr

Physics of Non-Newtonian Fluids

April 8, 2016

Non-Newtonian Fluids

In order to comprehend the non-Newtonian fluids’ concept, it’s important to first recall what we have learnt about Newtonian fluids during our Physics tuition classes. In reference to Newton’s theory, under normal pressure and temperature, fluids possess viscosity or steady flow and simply takes the shape of the container where they’re poured into. The fluids that meet both the conditions are identified as ‘Newtonian fluids’.

On the other side, advanced study in the fluid mechanics field showed that there are some non-homogenous fluids that show a change in viscosity state or a change in their state upon the application of shear-stress. These fluids can be classified as non-Newtonian fluids.


Shear thinning: This is one of the very most useful qualities of some non-Newtonian. Such fluids, when exposed to fast rising stress become rare in consistency as a result of the fluid particles sliding over each other.

Thixotropy: Thixotropic plastics, or simply Pseudo-plastics, are the fluids that encounter viscosity decrease with reference to the time duration for which shear-stress had been applied to them.

Shear thickening: Opposite to the shear thinning behavior shown by some non-Newtonian fluids, there are significant few fluids that have a tendency to act like solids because of the large size of its making up particles under swift stress. While delayed and slow movement assists the particles in flowing.

Rheopecty: Dilatant materials are materials whose shear-stress depends entirely on the time of its own application. Viscosity in dilatants increases with the time that the fluid is kept under the shear-stress. This fluids’ behavior is referred to as rheopecty.

Bingham plastics: These are materials which possess a linear shear-stress against shear rate characteristics. They have to reach a threshold shear-stress value before they start flowing. Provided that the shear-stress applied is below the threshold value for that particular material, it keeps its initial solid state.


The non-Newtonian fluids have actually exposed another world in the materials science field and its particular applications. There are a lot of natural events that show how helpful non-Newtonian fluids have been to the world. Motivated by these, researchers have ventured into the applications of non-Newtonian fluids in the daily lives. Furthermore, it has assisted science explain several of the tragedies and dangerous nature phenomenon and find strategies of fighting them. These applications include:

– To offer a flexible basis to the constructed structures/buildings in earthquake-prone regions to minimize the effect of the vibrations on the constructions in the course of an earthquake.

– To produce a body-suit flexible enough to permit body movements but shield the wearer from the fast physical impact of weaponry.

– Use for educational and recreational purposes.

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