The flow distribution behaviour of open-cell metallic foam fuel cell flow-fields are evaluated using ex-situ optical analysis and X-ray computed tomography (X-ray CT). Five different manifold designs are evaluated and flow distribution and pressure drop quantitatively evaluated with reference to applications in polymer exchange membrane fuel cells (PEMFC) and heat exchangers.

A ‘hybrid’ foam flow-field is presented consisting of flow channels pressed into the foam to promote flow distribution and reduce pressure drop. Cross- and through-channel pressure drop measurements are conducted, along with X-ray CT analysis.

Results using dyed water show that metallic foams provide excellent fluid distribution across the fuel cell flow-field, closely following the theoretical filling rate. The time for dye to cover 80% of the flow-field area was 61% faster with a foam flow-field then with no flow-field present. Pressure drop was seen to reduce with increasing foam inlet area to levels comparable to multi-serpentine flow-fields. The introduction of flow channels in the foam can further reduce pressure drop and provide more even filling of the foam, at the expense of increased residence time.

使用异位光学分析和X射线计算机断层扫描（X射线CT）评估开孔金属泡沫燃料电池流场的流动分布行为。参照聚合物交换膜燃料电池（PEMFC）和热交换器中的应用，对五种不同的歧管设计进行了评估，并对流量分布和压降进行了定量评估。

提出了一种“混合”泡沫流场，其由压入泡沫中的流动通道组成，以促进流动分布并减少压降。进行跨通道和通过通道的压降测量，以及X射线CT分析。

使用染色水的结果表明，金属泡沫在整个燃料电池流场中提供了出色的流体分布，非常接近理论填充率。染料覆盖泡沫流场的时间比不覆盖流场的时间快了61％，覆盖了流场面积的80％。可以看到，随着泡沫入口面积的增加，压降降低到与多蛇形流场相当的水平。在泡沫中引入流动通道可以进一步减少压降，并以增加的停留时间为代价提供泡沫更均匀的填充。