A numerical study of unstable Hele-Shaw flow

A numerical procedure which is based on an integral equation for the normal velocity at the interface is developed for the unstable flow with surface tension in a Hele-Shaw cell. The procedure has been validated by comparing solutions obtained by it with published results. It has also been applied to a study of the effect of small changes in the initial data on the later profiles and it was found that even very small differences can lead to large differences in the profiles at later times.