Effect of hydrodynamic and electrical parameters on the dynamics of bubble ascent in the presence of an electric field

Abstract

The present study numerically investigates the dynamics of bubble ascent under the influence of a horizontally applied electric field. We have developed an in-house electrohydrodynamics solver integrated with the open-source solver interFoam. This solver underwent meticulous validation against existing literature and was then employed for conducting simulations. Our investigation reveals the impact of the electric capillary number (CaE) on the occurrence of wobbling. Higher (CaE) values induce wobbling in various steady-state bubble shapes, including ellipsoidal, ellipsoidal cap, dimpled ellipsoidal, and bi-oblate. For the selected conductivity (R) and permittivity ratios(S), (CaE) exhibits negligible influence on bubble rising velocity. However, its effect on deformation is significant for ellipsoidal and ellipsoidal cap shapes while marginal for other configurations. (CaE) minimally affects the shape alteration of the bubble until the onset of wobbling. The overall influence of Bond number (Bo) and Reynolds number (Re) on the dynamics of bubble ascent in the presence of an electric field mirrors their impact in its absence, with one notable exception—the occurrence of wobbling. Wobbling is observed at lower Bo and Re values compared to their counterparts in the absence of an electric field.