Flow of a Nonlinear Viscoplastic Fluid in a Plane Channel
The analysis of mechanical behavior of concentrated suspensions of finely dispersed particles has been carried out. The results show that the viscosity of such medium does not depend monotonously on the shear rate. A combined type rheological model for viscoplastic working media of this kind is proposed, which suggests three characteristic behaviors at three contiguous ranges of shear rate change. In the first range, the dependence of shear stress on shear rate is described by a linear function and characterized by a constant viscosity value. At the second and third shear rate ranges, this dependence is approximated by non-linear functions describing dilatant and pseudoplastic behavior. On the basis of such a model, the solution to the steady-state fluid flow in a flat channel has been obtained. The analysis of the influence of the main parameters of the system on the velocity distribution characteristics has been carried out.