Electrohydrodynamic effects on bubble dynamics during nucleate pool boiling under the leaky dielectric assumption

Abstract

In this paper, a numerical investigation of bubble dynamics during nucleate pool boiling is conducted using the lattice Boltzmann method (LBM). Unlike the perfectly dielectric fluid assumption used in most previous studies, the leaky-dielectric model (LDM) used in this work allows free charges to accumulate at the gas-liquid interface and more closely models the real physical situation. The fully coupled equations are solved by combining the pseudopotential LBM with the phase-change model and the LDM. The numerical model is validated using four fundamental cases and the results agree well with benchmark data. Then, the influences of the deformation mode; electric field strength; and conductivity and permittivity ratios (R, S) are investigated. The electric field can deform the bubble into both prolate and oblate shapes, leading to acceleration and deceleration, respectively, of bubble departure from the hot surface. An optimum combination of (R, S) is identified that produces the best acceleration effect for bubble departure.