Direct numerical simulation of two-phase turbulent flow in fuel cell flow channel

Abstract

For high-performance low-temperature fuel cells (e.g. hydrogen proton exchange membrane fuel cell for powering vehicles), significant amount of reactant needs to be supplied, leading to turbulent two-phase flow, which is largely ignored in previous studies. In this study, a direct numerical simulation (DNS) model of the two-phase turbulent flow in fuel cell flow channel is developed with a modified volume-of-fluid (VOF) approach for tracking the air/water interface. The turbulent flow inlet of the two-phase DNS model is obtained from a validated single-phase DNS model. By resolving the whole range of spatial and temporal scales of turbulence, the results of the two-phase DNS model show that the deformation of water droplet is asymmetric and broken into small pieces/films, and is significantly different from the laminar and the corresponding k−ε models. It is suggested that the turbulence effect on the two-phase transport in fuel cell flow channel is significant and needs to be considered for water management by using the DNS model.