e Afshari - Mechanical Engineering Department, Faculty of Engineering, University of Isfahan, Isfahan, Iran
y Mollayi Barzib - Mechanical Engineering Department, Islamic Azad University, Kashan branch, Kashan, Iran

The purpose of present study is to investigate the dynamic response of two conventional types of solid oxide fuel cells to the inlet air mass flow rate variation. A dynamic compartmental model based onCFD principles is developed for two typical planar and tubular SOFC designs. The model accounts fortransport processes (heat and mass transfer), diffusion processes, electrochemical processes, anode and cathode activation and ohmic polarizations, among others. Using developed model, the dynamicresponse of the cell to the step change of the air feed stream conditions is investigated. The resultsshow an almost slow electrical response of the cell to the air mass flow rate step variation which is estimated to be about one hour. Moreover, it can be concluded that the effect of the inlet air flow conditions on a tubular solid oxide fuel cell performance is more noticeable than its effects on a planarSOFC. However, the electrical response time of the tubular type SOFC is calculated about ten times more than the planar type.

Solid Oxide Fuel Cell , Tubular Cell , Planar Cell , Dynamic Simulation , Time Constant