A new technique for the advection of liquid domains with free surfaces
is developed. This technique is based on describing the liquid surfac
e by a spine function h(alpha, t), with a being the angle measured fro
m one axis at time t. After discretization, the spines h(i)(alpha(i),
t(i)) subdivide the liquid zone into conical subvolumes. The volume of
each of the subvolumes is updated using the local velocities at the i
nterface of every two neighboring subvolumes. A technique is developed
to calculate the new spines based on the updated subvolumes. The meth
od is referred to as the spine-flux method (SFM) and it is implemented
in a Galerkin finite element method with penalty formulation. The pro
blems of drop oscillation and drop collision are utilized to show the
accuracy and efficiency of the technique. (C) 1995 Academic Press, Inc
.