2000

Authors Housiadas K., Tsamopoulos J. Abstract The unsteady extrusion of a viscoelastic film from an annular and axisymmetric die is examined. This moving boundary problem is solved by mapping the inner and outer liquid/air interfaces of the extruded film onto fixed ones, and by transforming the governing equations accordingly. The […]

Authors Housiadas K., Tsamopoulos J. Abstract The unsteady extrusion of a viscoelastic film from an annular and axisymmetric die is examined, when the gravitational and the capillary forces in the film are small relative to the viscous forces. The Oldroyd-B constitutive equation is employed. This moving boundary problem is solved […]

Authors Housiadas K., Tsamopoulos J. Abstract The unsteady extrusion of a viscoelastic film from an annular and axisymmetric die is examined. External, elastic, viscous and inertia forces deform the film, which is simultaneously cooled via forced convection to the ambient air. This moving boundary problem is solved by mapping the […]

Authors Housiadas K., Georgiou G., Tsamopoulos J. Abstract The steady extrusion of a Newtonian liquid through an annular die and its development outside and away from the die are studied under the influence of gravitational and surface tension forces. The finite element method (FEM) is used for the simulations. The […]

Authors Kouris C., Tsamopoulos J. Abstract The concentric, two-phase flow of two immiscible fluids in a tube of sinusoidally varying cross section is studied. Assuming that the tube radius is much smaller than the period of the constriction, the Navier-Stokes equations in each phase are simplified accordingly. This geometry is […]

Authors Smyrnaios D.N., Pelekasis N.A., Tsamopoulos J.A. Abstract The steady two-dimensional laminar flow of an air stream, flowing past a solid surface at high Reynolds number, is examined in the presence of rainfall. As raindrops sediment on the surface they coalesce and form a continuous water film that flows due […]