Here is a simple applet to simulate the drainage
of a thin film down a vertical substrate. The liquid is assumed Newtonian,
The initial profile is prescribed as a parabolic
mound superimposed on a thin wetting layer. The thickness of the mound
and of the wetting layer as well as the substrate length are all adjustable
- viscosity (poise),
surface tension (dynes/cm),
and specific weight (gm/sec2/cm2).
The run parameters are
the number of nodal points,
the time step (in seconds),
the maximum (physical) time (in seconds) after which the simulation is
to be stopped,
the rate of graphical output (in seconds).
After clicking the run button, the applet
opens a graphical window which displays the evolution of the film at the
specified instants. The simulation can be stopped, and a new run can be
performed. The reset button erases the graphics and all input
fields of the panel.
By pressing the fill button,
the axes can be adjusted to make the entire plot visible in the
A rectangle can be drawn in the graphics panel to zoom in any portion
of the plot.
A more general applet with the following capabilities:
can be found here .
3D simulation of the flow of a liquid film over
a flat substrate with variable inclination with respect to the vertical,
Generalized Newtonian rheology (Ellis viscosity
model, shear-thinning effect, etc),
Arbitrary initial profile of film thickness,
Adjustable liquid/solid contact angle,
Variable time stepping (acceleration scheme),
Contour graphics of surface elevation, cross-sectional