Аннотация
The paper deals with new approaches to the mathematical description of the flow of thick suspensions and sediments taking into account the experimentally observed characteristics of the flow of such systems. Since even very thick suspensions with the maximum solids content can be referred to dense sediments that have fluidity, we propose the modern model that allows describing this phenomenon and eliminating the corresponding limitations of known models. The submitted model describes the fluidity of the medium in a wide range of the content of dispersed solid phase even at its high concentrations in the suspension with account of features of the flow near a solid wall. Such result has been achieved thanks to a new heuristic expression for calculating the relative viscosity of the suspension as a function of the concentration of the solid phase. This approach allows also to describe flows of thick suspensions with free moving surfaces, taking into account the violation of the slip condition for a viscous fluid flows with solid inclusions near a solid wall. As shown by numerical experiment the offered model demonstrates good qualitative agreement with experimental observations. However it requires a more detailed analysis of the array of experimental data in order to clarify a number of control parameters applied to specific physicochemical systems.