Intern rapport

Modelling the current distribution and two-phase flow along a vertical gas-evolving hydrogen electrode

Abstract

The bubbly two-phase flow and electric current distribution along a single, vertical, gas-evolving electrode are considered. The two-phase flow model is coupled to the ionic species transport via the effective conductivity of the bubble suspension, which empirically depends on the gas fraction, and via the electrode overpotential. The latter essentially determines the charge transfer rate along the electrode and thereby, through Faraday`s law, the gas evolution rate. Existing empirical models for particle transport in sheared and sedimenting suspensions are adopted for the bubble mixture to close the two-phase model. The non-uniform conductivity of the bubble electrolyte along the electrode results in a non-uniform current distribution, which agrees well with existing experimental findings in literature.