In this work, the effect of the flow direction on a newly designed 100 cm(2) cell frames with internal flow channels for molten carbonate fuel cells (MCFCs) was investigated using three-dimensional fluid dynamic analysis. Simulation results were compared with the experimental results for verification. From the simulation, the performance, pressure drop, flow field, and gas mole fractions inside the cell frame were studied. In the performance of the single cell, only small difference was observed between co-flow and counter-flow; however, counter-flow resulted in a more uniform distribution of the current density without any hot-spots. For counter-flow, a uniform distribution of the current density could be achieved by controlling the current density or gas utilization. (C) 2016 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.