A computational analysis on the operational behaviour of open-cathode polymer electrolyte membrane fuel cells Anand Sagar a,b , Sachin Chugh b , Kapil Sonkar b , Alok Sharma b , Erik Kjeang a,* a School of Mechatronic Systems Engineering, Simon Fraser University, 250-13450 102 Avenue, Surrey, BC, V3T 0A3, Canada b Alternative Energy Department, Indian Oil R&D Centre, Sector-13, Faridabad, 121002, India highlights graphical abstract  A 3D computational model is developed and validated for open- cathode fuel cells.  The model reveals the unique hygrothermal characteristics of open-cathode cells.  Specific differences between liquid cooled and open-cathode cells are investigated.  Membrane drying and slow ki- netics cause inferior performance in open-cathode cells. article info Article history: Received 2 June 2020 Received in revised form 11 September 2020 Accepted 17 September 2020 Available online xxx Keywords: Fuel cell Open cathode Air cooling Performance Modelling Simulation abstract In the present work, a comprehensive, three-dimensional computational fuel cell model is developed, validated, and utilized to study the operational and hygrothermal behaviour of an open-cathode (air cooled) polymer electrolyte membrane fuel cell at various ambient conditions compared to conventional liquid cooled cells and a hypothetical isothermal case. The spatial distributions of relative humidity, temperature, and membrane water content are analysed during operation of the cell and the strong hygrothermal character- istic of the open-cathode fuel cell system is established. The high temperature and relative humidity gradients inside the cell are found to limit the cell performance for open-cathode cells unlike the other operational cases. Moderate self-heating followed by membrane drying is found to be the key factor limiting the net cell performance while in operation at moderate-to-high current densities and high air flow rates. The open-cathode fuel cell is also found to perform better at high temperature and high relative humidity ambient conditions; however, in contrast to liquid cooled cells, the performance is restricted by inefficient thermal and water management. * Corresponding author. E-mail address: ekjeang@sfu.ca (E. Kjeang). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (xxxx) xxx https://doi.org/10.1016/j.ijhydene.2020.09.133 0360-3199/© 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article as: Sagar A et al., A computational analysis on the operational behaviour of open-cathode polymer electrolyte membrane fuel cells, International Journal of Hydrogen Energy, https://doi.org/10.1016/j.ijhydene.2020.09.133