The yield stress ([t.sup.0]) and plastic viscosity ([[mu].sub.pl.]) were determined in the course of linear approximation of flow curves (dependence between shear stress ([tau]) and shear rate ([gamma]) in the range from 0.1 to 100 [s.sup.-1] based on the
Bingham model. The
Bingham model is a more widely used model for description of flow behavior of cement systems, which is expressed by following equation:
Cazacliu, "Analysis of a regularized
Bingham model with pressure-dependent yield stress," Journal of Mathematical Fluid Mechanics, vol.
Bingham Model. The Bingham and Herschel-Bulkley models are commonly applied in paste rheology.
We assume that the debris flow impinging on an obstacle is 2-dimensional (2D), based on
Bingham Model and unaffected by the dynamics of run-up on the obstacle.
Under the effect of magnetic field, MRF is a kind of plastic fluid and confirms to
Bingham model. Similarly, magnetic liquid also conforms to
Bingham model [14].
The Ishlinsky model also transforms itself into the
Bingham model on the same condition, i.e.
As far as
Bingham model is adequate to characterize rheological properties of fresh mortar and concrete, characterization of rheological properties of cement paste demands more complex models.
If in the
Bingham model we do not take into account the damping force and take into account the constant force P in one direction--in compression phase, the tensile stress does not appear.
To describe concrete flow behavior, both yield stress and plastic viscosity, as defined by the
Bingham model, are key properties that should be determined.
The Herschel-Bulkley model is a generalized form of the
Bingham model, where the linear shear-rate dependence is replaced by a power-law behaviour.
In previous studies, paste-like tailings slurry (PLTS) was simplified as a Bingham plastic fluid, whose flow properties were time-independent, and the existing empirical formulas for calculating the hydraulic gradient of a paste-like flow were derived based on the time-invariant
Bingham model [7].
It is also observed while dealing with
Bingham Model; three different zones in the flow domain can be identified