Every fluid behaves differently
according to particle size, shape, distribution, particle volume fraction, particle-particle
interaction. There are some external parameters also that affect the behaviour
like type, rate, and time of deformation. The fluids are categorized in time
dependent (thixotropic and rheopectic) and time independent (Newtonian and
non-Newtonian fluid).
1. Thixotropic: Viscosity
decreases with time of deformation, that does not get thicken with time like paint should be thixotropic
2. Rheopectic: Viscosity
increases with time of deformation
3. Newtonian Fluid: Viscosity
remains constant with time and rate of deformation
4. non-Newtonian
Fluid:
a) Dilatant: Viscosity
of fluid increases with rate of shear that doesn't get diluted i.e. shear thickening. These type of
fluids can be used to make bullet proof jacket i.e. when force is applied it
will behave like a solid. One more application can be in the knee joint, where
we need a material that acts like a solid when we rest and act like a lubricant
when we move.
b) Pseudoplastic: Viscosity
of fluid decreases with rate of shear i.e. shear thinning. Like toothpaste,
when we hold it in upside down, it will not come out, but when we apply a
force, it starts coming. i.e. viscosity of the paste decreases.
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