Investigating Inlet Condition Effects on PEMFC GDL Liquid Water Transport through Pore Network Modeling
In a fuel cell stack, the cell components are assembled under compressive loads to prevent gas leakage; however, high compression of the GDL may affect cell performance. The non-uniform compression of the GDL, due to its contact with the bipolar plate, significantly alters the microstructure and consequently the dynamics of liquid water transport through the GDL . A number of attempts have been made in experimental visualization of liquid water transport within compressed GDLs, but more work is required to evaluate these effects quantitatively [1-3].
The purpose of this study is to numerically investigate the effects of compression on liquid water transport through PEMFC GDLs. In this work, two types of carbon paper GDLs are compressed. At each compression value, volumetric X-ray tomography images of the samples are obtained. The resulting greyscale images are segmented using a novel thresholding algorithm. A watershed algorithm  is used to extract pore networks of the GDL. Pore network modeling with invasion percolation is employed to determine the liquid water profile within the GDL over the range of compression states. The results of this study provide a deeper knowledge of how compression and the GDL microstructure affect the movement of liquid water.
 Bazylak, A., Sinton, D., Liu, Z.-S., Djilali, N. (2007) “Effect of Compression on Liquid Water Transport and Microstructure of PEMFC Gas Diffusion Layers,” Journal of Power Sources, 163 (2), 784-792
 Yip, R., Bazylak, A. (2012) “Investigation of liquid water saturation of compressed PEMFC GDLs using micro-computed tomography.” ESFuelCell2012-91446, American Society of Mechanical Engineers (ASME), 10th International Fuel Cell Science, Engineering and Technology Conference, San Diego, California, July 23-26, 2012
 Challa, P., Hinebaugh, J., Bazylak, A. (2011) “Comparison of Water Thickness Profiles of Compressed PEMFC GDLs.” ESFuelCell2011-54340, American Society of Mechanical Engineers (ASME), 9th International Fuel Cell Science, Engineering and Technology Conference, Washington, D.C. August 7-10, 2011
 Hinebaugh, J. Bazylak, A. (2012) “Pore Network Modeling to Study the Effects of Common Assumptions in GDL Liquid Water Invasion Studies.” ESFuelCell2012 -91466, American Society of Mechanical Engineers (ASME), 10th International Fuel Cell Science, Engineering and Technology Conference, San Diego, California, July 23-26, 2012