Static and dynamic response of a fluid–fluid interface to electric point and line charge

Abstract

We consider the behavior of a dielectric fluid-fluid interface in the presence of a strong electric field from a point charge and line charge, respectively, both statically and, in the latter case, dynamically. The fluid surface is elevated above its undisturbed level until balance is reached between the electromagnetic lifting force, gravity and surface tension. We derive ordinary differential equations for the shape of the fluid-fluid interface which are solved numerically with standard means, demonstrating how the elevation depends on field strength and surface tension coefficient. In the dynamic case of a moving line charge, the surface of an inviscid liquid-liquid interface is left to oscillate behind the moving charge after it has been lifted against the force of gravity. We show how the wavelength of the oscillations depends on the relative strength of the forces of gravity and inertia, whereas the amplitude of the oscillations is a nontrivial function of the velocity at which the line charge moves. * Corresponding author.Email addresses: simen.a.ellingsen@ntnu.no (SimenÅ. Ellingsen), iver.h.brevik@ntnu.no (Iver Brevik) 1 Fax number: +47 73593491. Telephone: +47 73593554.

Dynamics of a nanodroplet under a transmission electron microscope

“…Therefore, the assumed periodicity may not accurately reflect the actual heterogeneities present in the real substrate. Future work should include an accurate model of electron beam stresses on the drop 43 and elucidating the nanoscale heterogeneity patterns on substrate surfaces.…”