Phase-Field Modeling and Simulation of Gas Bubble Coalescence and Detachment in a Gas-Liquid Two-Phase Electrochemical System

Abstract

Many electrochemical processes involve gas evolution and bubble generation on the electrodes. Understanding the behavior of bubbles on the electrode surface and in the electrolyte is crucial to the design and optimization of the electrochemical process. Gas bubbles tend to coalesce and detach from the electrode surface once they are formed and as they grow, but these processes have not been investigated and understood well. The phase-field modeling method is excellent at tracking the interface between different phases, and the simulation results can give a precise prediction of the interaction between phases. In this research, taking advantage of the phase-field method, a gas-liquid two-phase model has been constructed to investigate the bubble coalescence and detachment in the electrochemical system. Sophisticated, tiny gas bubble coalescence on and off electrode and the detachment of bubbles from the electrode surface were predicted by the model. The results are helpful for the understanding of these transient processes in the electrochemically generated bubble-liquid system.