*Corresponding author, e-mail: bilgili@gazi.edu.tr DOI: 10.29109/gujsc.623951 GU J Sci, Part C, 7(4): 999-1011 (2019) Gazi Üniversitesi Fen Bilimleri Dergisi PART C: TASARIM VE TEKNOLOJİ http://dergipark.gov.tr/gujsc Numerical Analysis of Two Units PEM Fuel Cell Stack Tugay ARIÇ 1, , Muhittin BİLGİLİ 2,* , Abuzer Kadir ÖZSUNAR 3, 1,2,3 Gazi University, Faculty of Engineering, Department of Mechanical Engineering, 06570, Maltepe/ANKARA Article Info: Graphical/Tabular Abstract In this study, PEM fuel cell stack is analyzed by numerically. By using the same cell dimensions, electrochemical and physical properties at each layer of the cell, a PEM fuel cell stack is designed and prepared. Each cell has 5.4 cm 2 active area and connected in series. Reactants of anode and cathode flow direction is preferred parallel. PEM fuel cells are accepted as operating conditions of 70 o C and 1 atm. Polarization curves and electrical power curves are obtained for different current densities values of single and stack of PEMFC. Figure A. Electrical power curves corresponding to current density for single and two cells Purpose: In this study, single and two unit PEM fuel cell stack are analyzed numerically and electrical power values calculated. Thereby it is observed that number of fuel cell units effects on the electrical power. It is also obtained how effectively increasing electrical power for two different number of fuel cell unit. Theory and Methods: In this study, PEMFC single cell and stack models has been designed by CATIA V5R21. These designed cell models were analyzed for single and stack cell using ANSYS FLUENT. Results: The maximum electrical power values obtained from two cells stack and single cell were calculated as 11.32 W and 6.26 W, respectively. It is observed when the number of units in the PEMFC is increased, it is attained more electrical power nearly at the same range. Reasons of the losses in the electrical power are estimated as friction, ohmic losses or rising of fluid cover distance. Conclusion: Design and analysis of one and two units PEMFC are investigated in this study. And it has been observed when the cell number is increased from one to two cells, electrical power is increased about the same amount. Moreover, the distribution of reactants in the channels, temperature distributions, current density distributions and water saturation at selected cross sectional area for a two units fuel cell stack is analyzed at the different voltage values. Research article Received: 24/09/2019 Revision 19/11/2019 Accepted: 27/11/2019 Highlights • PEMFC stack modelling • Electrical power curve • CFD analysis of fuel cell Keywords PEM Fuel Cell Bipolar Plate Fuel Cell Stack 0 2 4 6 8 10 12 14 0 1 2 3 Electrical Power (W) Current Density (A/cm 2 ) two cells Single cell