  Volume of fluid(VOF) method is a sharp interface method employed for
simulations of two phase flows. Interface in VOF is usually represented using
piecewise linear line segments in each computational grid based on the volume
fraction field. While VOF for cartesian coordinates conserve mass exactly,
existing algorithms do not show machine-precision mass conservation for
axisymmetric coordinate systems. In this work, we propose analytic formulae for
interface reconstruction in axisymmetric coordinates, similar to those proposed
by Scardovelli and Zaleski (J. Comput. Phys. 2000) for cartesian coordinates.
We also propose modifications to the existing advection schemes in VOF for
axisymmetric coordinates to obtain higher accuracy in mass conservation
