Hydromechanical nature of bulk materials movement in vertical pipe of round and square cross-sections

The traditional gravitational flow of bulk materials has been researched in the vertical pipe of round and square cross-sections on the basis of the viscous fluid model. We assume that the medium viscosity ratio is proportional to the pressure in a given point. Such dependence of viscosity results in the fact that the mass flow rate per unit time does not depend on the height of the column of bulk material. When in steady motion, the dependence of pressure on a vertical coordinate and the distribution of a medium velocity’s vertical component in the cross-sections of pipes has been obtained theoretically. It is shown, that there is a pressure limit some distance away from the free surface of bulk materials. The results obtained via theoretical predictions coincide with ones obtained experimentally. The results for the gravitational flow of bulk materials in pipes are generalized to the movement of such materials along an inclined plane.