A simplified computational scheme that can be efficiently applied to predict fully developed axial flow in rod bundle subchannels is presented and compared with experimental results for different flow conditions. Galerkin's finite element method and the physical model of turbulence proposed by Roco and Zarea (1978) are used in this approach.The flow in the corner, wall, and central subchannels for both triangular and square rod bundles is investigated. Different values of the subchannel pitch-to-diameter ratio and various Reynolds numbers are considered. In all these cases, the present computational scheme gives the correct qualitative trends for the distributions of the axial velocity and wall shear stress. The comparison performed with current measurements in the subchannels of a 3×6 rectangular rod bundle and with other available experimental and analytical results taken from the literature shows good agreement.