Convergent Flows of Molten Polymers Modeled by Generalized Second-Grade Fluids of Power-Law Type

The molding processes of polymer melts involve geometrically complex dies. Such dies are usually tapered or streamlined to achieve a maximum output rate under conditions of laminar flow. The model of a generalized second-grade fluid of power-law type is used and the results obtained are illustrated by examples of convergent flows in conical and wedge-shaped dies.     

Pressure distribution in a porous squeeze film bearing lubricated by a Vočadlo fluid

The influence of a wall porosity on the pressure distribution in a curvilinear squeeze film bearing lubricated by a lubricant being a viscoplastic fluid of a Vo?adlo type is considered.     

Pressure Distribution in a Curvilinear Thrust Bearing with One Porous Wall Lubricated by a Bingham Fluid

The influence of wall porosity on the pressure distribution of a Bingham fluid flowing in the clearance of a curvilinear thrust bearing is considered. The formulae expressing the pressure distribution are obtained for two cases, namely: an externally pressurized bearing and a squeeze film bearing. The example of a squeeze film between parallel disks is discussed in detail.     

Inertia Effects in Squeeze Flows of Viscoplastic Fluids

A squeeze flow of a viscoplastic fluid through a narrow clearance between two coaxial surfaces of revolution is considered. The problem is described by boundary-layer equations. With the use of the method of integral approaches, formulas for the pressure distribution are obtained. Generally, the flow of viscoplastic fluids given by the nonlinear Shulman model is considered. The flows of viscoplastic fluids given by the Herschel, Bulkley, Bingham, Ostwald-de Waele, and Newton models are discussed in detail. Numerical examples of pressure distributions in the clearance between parallel disks are presented.