As the simplified manifold model has well-defined boundary conditions for conducting fluid dynamics simulations, it was used to assess the quality of simulation results gained with commercial CFD software. The complete branching system of inlet and outlet manifold tubes and the 32 tubes that represent the cells is reconstructed via the use of a CAD program and transferred to the CFD software tool, in this case AVL FIRE®. Discretization is performed by the finite volume method generating computational grids with more than 2∙106 hexahedral elements. Different types of meshes are tested as well as different turbulence models for case B. As already shown in literature, simulation results may strongly depend on the applied turbulence model [7].