Dynamics of Emerging Water Droplet Subjected to Sidewall with Different Wettabilities in a Fuel Cell Cathode Channel
✍ Scribed by X. Zhu; P. C. Sui; N. Djilali; Q. Liao
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 712 KB
- Volume
- 11
- Category
- Article
- ISSN
- 1615-6846
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✦ Synopsis
Abstract
On‐site experiments on low temperature fuel cells revealed that water droplets tend to emerge into the gas channel at the corner. This motivates the present investigation on the effects of the location where water emerges from and the wettability of sidewall on the dynamic behaviour of liquid water in gas channel by numerical simulations that employ the volume‐of‐fluid method. A microchannel with a square cross‐section of 0.25 mm in width and a pore of 0.05 mm in diameter is adopted. The simulation results for different pore locations and wettabilities of sidewall show that the behaviour of water droplet only depends on the wettability of bottom wall when it emerges from the centreline without attaching to the sidewall and gains the highest pressure drop. When the emergence location shifts towards the corner, the water droplet unavoidably attaches to the sidewall and thus the wettability of sidewall is found to have significant effects on its dynamics: hydrophobic sidewall results in droplet detachment and fast removal with the highest pressure drop and the minimal water saturation, whereas hydrophilic sidewall leads to a water film and accumulation with the lowest pressure drop and the minimal water coverage on the bottom wall.