2-DIMENSIONAL FLOW OF A LIQUID SHEET UNDER GRAVITY

An iterative FD technique is developed to simulate the free surface fl ow relative to a two-dimensional gravitational (or vertically falling) liquid sheet. Its features are: it is based on an orthogonal boundary fitted coordinate transformation; a streamfunction-vorticity formulat ion is adopted; the normal stress boundary condition is employed to up date the free interface shape within an iterative process. Inertia, vi scous, gravity and surface tension forces are all taken into account i n the present model and it is shown that different simplified flow reg imes can be conveniently identified according to the values of Reynold s and Stokes numbers. Indeed, the main peculiarity of the present pape r just lies in the relatively wider range of simulated Stokes values w ith respect to previous papers. Computed results (interface profiles, pressure distributions) well agree with available literature data for flows with and without gravity. From one hand the classical die-swell problem phenomenology is recovered, from the other one a discussion ab out the validity of the Adachi's theoretical model is yielded.