Drops within drops within drops

We consider a nested set of viscous drops in Stokes flow. We derive the system of equations governing the motion of the drops and of the fluid within them. We then present numerical simulations on the evolution of (a) a set of n initially concentric drops in a strainfield and (b) double drops moving through a constriction. Of interest in particular is the effect of the fluid viscosities on the internal strain rates and on the breaking of constrained drops.