Laminar Newtonian jets at high Reynolds number and high surface tension

Steady Flow of a Two-Dimensional Liquid Curtain Under Pressure

“…This value corresponds to an extrudate-swell ratio of 1.186 which agrees well with previous studies (Georgiou and Boudouvis, 1999), and indicates that the mesh refinement near the die exit is satisfactory. The effect of the gravitational force is important and results in considerable reduction of the film thickness, in agreement with previous work (Georgiou, Papanastasiou and Wilkes, 1988). The calculated upper free surfaces for the dimensionless numbers corresponding to the two experiments of Finnicum, Weinstein and Ruschak (1993) are plotted in Fig.…”

“…The objectives of the present work are: (a) to solve numerically the steady, two-dimensional flow of a planar Newtonian curtain issuing from a slit and under a pressure difference, taking into account gravity and surface tension effects; and (b) to make comparisons with the experimental film shapes provided by Finnicum, Weinstein and Ruschak (1993). The finite element method with the full-Newton iteration technique for the calculation of the unknown positions of the two free surfaces of the film is well established and is described elsewhere (Georgiou, Papanastasiou and Wilkes, 1988;Housiadas, Georgiou and Tsamopoulos, 2000;Georgiou, 2003). In Section 2, the governing equations and the boundary conditions of the flow are presented, and an outline of the finite element method used in the simulations is given.…”

Die Swell of Complex Polymeric Systems

“…The dispersed particles perturb the flow of the melt. It is interesting that this is consistent with previous publications showing that the dimensions of the extrudate were possibly smaller than those of the die at higher Reynolds numbers [41,42].…”

“…However, at higher Reynolds numbers, the dimensions of the extrudate are possibly smaller than those of the die. Few data have been published concerning the effect of Reynolds number on the die swell [41,42]. Han [29] suggested that the equilibrium die swell measurements are independent of rheometer geometry for common extrusion at relatively low flow rate through a capillary where the ratio of reservoir diameter to capillary die diameter is less than 10, and length to diameter ratio of the capillary die is greater than 20.…”

The VOF method applied to the numerical simulation of a 2D liquid jet under gravity

“…In the absence of gravity, at high Reynolds numbers the sheet contracts, whereas at low Reynolds numbers due to the sudden change of the boundary conditions on the viscous stresses, the sheet expands in the near field (die-swell effect, see Georgiou et al [1]). Other important effects affecting the dynamics of the jet are surface tension and gravity.…”