This research project aims to study

This research project aims to study gas permeability of PEMFC gas diffusion layers (GDLs). Six GDL samples including carbon cloth and carbon paper with and without PTFE coating were tested to study effects of GDL structure and PTFE loading on GDL permeability. Small wind tunnel was built to measure air flow rate and pressure drop across the GDL thickness. The measured flow rate and pressure drop were employed to calculate the gas permeability using Darcy's model. The resulting permeability was also compared with the permeability calculated using Tomadakis-Sotirchos (T-S model). The main findings are as following. 1) The cloth GDL is about 52 times higher in permeability than the paper GDLs. 2) PTFE coating has a great impact on GDL permeation by decreasing the permeability up to 56% from the uncoated GDL. 3) For the paper GDL, the permeability calculated using T-S model closely agree with the results calculated by Darcy's model. For the cloth GDL, the calculated permeability differ considerably between these models, approximately 67% difference, indicating T-S model might inappropriate for cloth GDL permeability prediction.

This research project aims to study gas permeability of PEMFC gas diffusion layers (GDLs). Six GDL samples including carbon cloth and carbon paper with and without PTFE coating were tested to study effects of GDL structure and PTFE loading on GDL permeability. Small wind tunnel was built to measure air flow rate and pressure drop across the GDL thickness. The measured flow rate and pressure drop were employed to calculate the gas permeability using Darcy's model. The resulting permeability was also compared with the permeability calculated using Tomadakis-Sotirchos (TS model). The main findings are as following. 1) The cloth GDL is about 52 times higher in permeability than the paper GDLs. 2) PTFE coating has a great impact on GDL permeation by decreasing the permeability up to 56% from the uncoated GDL. 3) For the paper GDL,. the permeability calculated using TS model closely agree with the results calculated by Darcy's model. For the cloth GDL, the calculated permeability differ considerably between these models, approximately 67% difference, indicating TS model might inappropriate for cloth GDL permeability prediction.

This research project aims to study gas permeability of PEMFC gas diffusion layers (GDLs). Six GDL samples including carbon. Cloth and carbon paper with and without PTFE coating were tested to study effects of GDL structure and PTFE loading on GDL. Permeability. Small wind tunnel was built to measure air flow rate and pressure drop across the GDL thickness. The measured. Flow rate and pressure drop were employed to calculate the gas permeability using Darcy 's model. The resulting permeability. Was also compared with the permeability calculated using Tomadakis-Sotirchos (T-S model). The main findings are as, following. 1) The cloth GDL is about 52 times higher in permeability than the paper GDLs. 2) PTFE coating has a great impact on GDL. Permeation by decreasing the permeability up to 56% from the uncoated GDL. 3) For the, paper GDL the permeability calculated. Using T-S model closely agree with the results calculated by Darcy 's model. For the cloth GDL the calculated, permeability. Differ considerably between these models approximately 67%, difference indicating T-S, model might inappropriate for cloth. GDL permeability prediction.