In this study the effects of shear stress distribution and pressure loss on two different hollow fiber module types through have been investigated. The CFD simulations are based on the numerical solutions of the Reynolds averaged Navier-Stokes equations on three dimensional module geometries. The fluid flow inside modules is modeled using a realizable k-epsilon turbulence model. Module geometries consist two different types of inlet and outlet. One of the modules has normal and the other has tangential inlet and outlet. These two module types are investigated by CFD simulations and results are verified with experimental studies. Based on the simulation results, it has been observed that tangential inlet and outlet create rotational flow inside the module and this causes higher shear stress when compared to normal module geometry. The velocity profiles inside the modules and average pressure drop between inlet and outlet ports are presented. For tangential module configuration, the distribution of velocity inside the module is more homogeneous than the normal module configuration. Average pressure drop between inlet and outlet ports for both module configurations is nearly the same in steady state simulations. The results of the experimental studies are in accordance with the simulation results. (C) 2014 Elsevier B.V. All rights reserved.