Effect of an electric field on capillary waves

Jason Koski

Sandia National Laboratories

Utilizing the LAMMPS simulation package, the role of an external electric field on capillary waves in a dipolar fluid is investigated using molecular dynamics simulations. For fields parallel to the interface, the suppression of the capillary wave is significantly larger than given by the zero field relation for the amplitude of the capillary waves and the surface tension. For fields perpendicular to the interface, the opposite effects occur for low field strengths; the amplitude of the capillary waves increases more than predicted by the increase in surface tension. Furthermore, the interface becomes unstable above a critical perpendicular field strength that decreases as the interface length increases due to the increased amplitude of the capillary waves. This simulation study demonstrates just one example of many possible dipolar systems with or without an external field that can be analyzed using LAMMPS.‚Äč