Analysis of droplet vibration dynamics in two-dimensional/three-dimensional flow field of fuel cells

Abstract

This study used the two-dimensional fluid volume method to investigate the effect of vibration on the detachment and removal of droplets in the two-dimensional/three-dimensional flow channel of proton exchange membrane fuel cell (PEMFC). The vibration frequency was used as the main variable to study the dynamic process of droplets in the channel, and typical droplet flow modes and separation methods were determined. The water removal ability of the two-dimensional/three-dimensional flow channel under vibration conditions was evaluated using droplet breakage time and coverage rate as evaluation indicators. Finally, the orthogonal table method was used to analyze the effects of vibration frequency, vibration amplitude, wind speed, and droplet size on the water removal ability of the three-dimensional flow field. The results indicate that under vibration conditions, the main motion modes of droplets are rolling mode and crushing mode and that the drainage capacity of the three-dimensional flow field is much higher than that of the two-dimensional flow field in both modes. The impact of vibration on the removal of droplets in the flow channel in the crushing mode is more significant compared to the rolling mode, and the vibration frequency has a greater impact on the drainage efficiency of the three-dimensional flow channel compared to the vibration amplitude. This study is of great significance for understanding the dynamics of droplets in PEMFC gas channels under vibration conditions as well as for optimizing the design and operating conditions of these channels.