From the equations above we see that
μp = \(\phi\) 600 – \(\phi\) 300,
μa = \(\frac{\phi 600}{2}\)
Where, μp is the plastic viscosity (Cp), which is the slope of the shear
stress (τ) vs. shear rate (γ) curve for both the Bingham and the
Newtonian models. μa is the apparent viscosity (Cp), \(\phi\) 600 is the
viscometer reading at 600 rpm, \(\phi\) 300 is the viscometer reading at
300 rpm .
The Newtonian curve intercepts at (0, 0) and would have a straight line
curve, τ = μp γ while the Bingham curve intercepts at (0, X) and would
have a straight line curve, τ = μp γ + X where X is the yield point of
the fluid and a point on the Y-axis. A Non-Newtonian fluid lies between
the Newtonian and Bingham curves.