Electrohydrodynamically driven chaotic mixing in a translating drop

When a liquid drop of given dielectric constant, resistivity and viscosity is translating in the presence of an electric field in a liquid of different dielectric constant, resistivity and viscosity, the resulting internal circulation is a superposition of the Hadamard–Rybcynski and Taylor (quadrapole) circulations. For sufficiently large field strengths, the quadrapole structure of the Taylor flow causes an internal stagnation disk to occur. When this flow field is modulated by an ac component of the electric field, at low Stokes numbers, the resulting Lagrangian particle trajectories can exhibit chaotic behavior. This Lagrangian chaos is examined via Poincare maps and both the degree and rates of mixing are studied for a wide range of field strengths and modulation frequencies.