Investigation of the unsteady flow of a dilating fluid with the Bulkley — Herschel yield strength in a cylindrical tube

In this work, the study of the unsteady flow of a dilatant fluid with the Bulkley — Herschel yield strength in a cylindrical pipe was carried out. The flow of a dilatant fluid with yield strength is characterized by increased values of effective viscosity at the inlet to the pipe, as well as in the axial and parietal flow zones. The increase in effective viscosity near the flow axis is explained by the viscoplastic behavior of the medium, near the wall by dilatant properties. As the flow stabilizes and the rate of shear deformations decreases, the high-viscosity zone localized near the inlet section degenerates; The effective viscosity in the axial zone increases, resulting in the formation of a quasi-solid flow zone