[Terminology] Plastic fluid (Bingham plastic fluid)
Time: 2014-12-11 20:46:07

[Terminology] Plastic fluid (Bingham plastic fluid)

Non-Newtonian fluid.

Not obey Newton’s law of viscosity.

Relationship of D(shear velocity) - τ(shear stress): there is a point of intersection with shear stress axis; value of the point is yield value τy.

Only when the shear stress τ is greater than the yield value τy, fluid flows.

 

When the shear stress τ is greater than the yield value τy, there are the following fluids states:

1 Ordinary plastic fluid

Obey Newton’s law of viscosity.

Relationship of D(shear velocity) - τ(shear stress) is straight line, but does not pass through the origin.

τ-τy=ηD

Common ordinary plastic fluids have toothpaste, paint and so on.

2 Nonlinear plastic fluid

Not obey Newton’s law of viscosity.

(1) Herschel-Bulkley fluid

Rheological properties obey exponential relationship.

τ-τy=KDn