Euler-Lagrangian modeling of H2 bubbly flows in an alkaline water electrolysis cell

• An Euler-Lagrange (E-L) model is established to model H 2 bubbly flow in AWE. • E-L simulations with RANS and LES predict very similar mean flow behavior. • Modeling turbulent dispersion force in bubble motion is crucial when using E-L RANS. • LES shows the turbulence-induced heterogeneous structure of bubbly flow. The hydrodynamic behavior of bubbly flows in alkaline water electrolysis (AWE) has received much attention since the behavior of bubbles influences the operating efficiency of electrolyzers. In this paper, we used the Euler-Lagrange approach to simulate the H 2 bubbly flow in an AWE cell and conducted a comparative analysis for turbulence models of RANS and LES. Our study shows that the distribution of bubbles appears more dispersed and spiral-structured in LES, due to the resolved turbulent eddies in the liquid phase. However without resolving the turbulence in RANS models, it is crucial to address the turbulent effect on bubble dynamics via effective modeling a so-called turbulent dispersion force for accurate prediction of the bubbly flow behavior. Furthermore, we show that when using RANS model with the turbulence dispersion model, both Euler-Lagrangian and Euler-Euler simulations give almost identical prediction of the mean flow behavior for homogeneous bubble size systems. Finally our simulations are validated with experimental results reported by Riegel et al. (1998), which also inspires directions for further model improvement. Overall, such an experimentally-validated E-L model is expected to contribute in understanding the mechanism of bubbly flows and guiding real-life optimization of AWE.