Numerical analysis on transition sequence and heat transfer capacity of film boiling with a uniform electric field.

This article focuses on the development and validation of a finite volume method solver for electric field-enhanced film boiling based on the OpenFoam v2012 framework. By coupling the Tanasawa model for phase change and the leaky dielectric model (LDM) for electrohydrodynamics, the study numerically investigates the influence of vertical electric fields on boiling flow patterns, transition sequences, and heat transfer capacity at different overheated temperatures (ΔT = 5, 10, and 20 K). Results show that at lower overheats, the system exhibits bubble pinch-off scenarios transitioning from periodic to chaotic flows with increasing electric field intensity, enhancing heat transfer by elongating bubbles and increasing detachment frequency. At higher overheats, a stable bubble column flow dominates, which is less affected by the electric field until chaotic flow emerges at very high field strengths, leading to a transition from film boiling to nucleate boiling and significant heat transfer enhancement. The maximum time-averaged Nusselt number achieved is 23.42, corresponding to a heat transfer enhancement ratio of approximately 5.08, demonstrating that chaotic flow states and bubble column scenarios yield superior heat transfer performance under electric field influence.