Thermal radiation in the air and fuel channels has the potential to dramatically influence the overall operating conditions and performance of solid oxide fuel cells. A 3D comprehensive model is developed, with emphasis on quantifying the radiative heat transfer process and its effects. The radiosity method is used for the thermal radiation in the air and fuel channels. The thermal radiation heat transfer is coupled to the overall energy conservation equation. Commercially available COMSOL CFD software is used as a platform for the global thermal-fluid modeling of the SOFC. The effects of the operating voltage, emissivity, ambient temperature and flow arrangement (Co- and Counter-flow) on the performance of SOFC are investigated. The predicted results reveal that the radiative heat transfer should be considered in SOFC modeling simulation, and the effects of the thermal radiation on the performance of SOFC under a different flow arrangement is sometimes quite significant. (C) 2012 Elsevier B.V. All rights reserved.