Hwang, Yong-Sheen Lee, Dae-Young Choi, Jong Won Kim, Seo-Young Cho, Sung Ho Joonho, Park Kim, Min Soo Jang, Jae Hyuk Kim, Sung Han Cha, Suk-Won 2024-01-20T19:33:11Z 2024-01-20T19:33:11Z 2021-09-02 2010-04 0360-3199 https://pubs.kist.re.kr/handle/201004/131594 This study investigates the enhancement of the oxygen diffusion rate at the cathode of a proton exchange membrane fuel cell (PEMFC) due to pure oscillating flow. A unit cell of PEMFC using hydrogen fuel and oscillating air was tested. The experimental results show that the non-dimensional effective diffusivity varies linearly with the square of the Womersley number, when the Womersley number is close to unity. The non-dimensional effective diffusivity varies linearly with the Womersley number itself when the Womersley number is much larger than unity. Similar trend has been confirmed from the theoretical approach. Under the experimental conditions in this study, the reaction rate of oxygen increased linearly with respect to the sweep distance. The experimental results showed that a power density of 115.4 mW/cm(2) was obtained from the unit cell with oscillating flow, which is comparable to that obtained with forced flow. Therefore, an oscillating flow is found to be able to increase the concentration of the oxygen in the channel of PEMFCs, and consequently enhances mass-transfer, similarly to the use of forced flow using blowers or compressors. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD MASS-TRANSFER ENHANCEMENT LONGITUDINAL DISPERSION WATER FREQUENCY Enhanced diffusion in polymer electrolyte membrane fuel cells using oscillating flow Article 10.1016/j.ijhydene.2010.01.064 1 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, v.35, no.8, pp.3676 - 3683 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 35 8 3676 3683 scie scopus 000277463600057 2-s2.0-77950369261 Chemistry, Physical Electrochemistry Energy & Fuels Chemistry Electrochemistry Energy & Fuels Article MASS-TRANSFER ENHANCEMENT LONGITUDINAL DISPERSION WATER FREQUENCY PEMFC Enhanced diffusion Oxygen concentration Oscillating flow Frequency Sweep distance