Pressure drops in the flow through an annular die of a polymer modelled by a Herschel-Bulkley fluid

Technologies applied in polymer processing require permanent improvement by better recognition of material properties of polymer, mechanisms of process and physical phenomena arising in processing. In the work a polymer flow in an annular die modelled as narrow clearance between two fixed surfaces of revolution is considered. The problem is described by boundary layer equations. Using the method of averaged inertia one obtains the formulae expressing the pressure distribution. Generally, the flow of polymer given by the nonlinear model of Shulman is considered. The molten polymer modelled by a Herschel-Bulkley model flowing through an annular spherical channel is discussed in detail.