The analytical solution to the boundary value problem described in Section 4.1 are linear profiles for the temperature and mass fractions of species A and B. Due to the varying thermal conductivity λ and diffusion coefficient D A,B of the solid and fluid phase, the slope of the profiles in the two domains is different resulting in a kink at the fluid-solid interface. Independent of whether the underlying mesh is structured or unstructured, the temperature and mass fraction profiles numerically calculated by applying the conjugated heat and mass transfer model at the fluid-solid interface agree excellently with the analytical solution, as shown in Figure . The deviation of the numerical from the analytical solution for the mass fraction of component A at the interface is 5.0 × 10 -5 % with a structured and 3.9 × 10 -4 % with an unstructured mesh, respectively. For the temperature at the interface, the numerical solution differs by 6.0 × 10 -9 % with the structured and by 1.3 × 10 -4 % with the unstructured mesh from the analytical solution. The higher deviation of the simulation based on a unstructured mesh can be attributed to the increase of numerical diffusion, when polyhedral computational cells, which are not aligned in the direction of the diffusive flux, are used instead of orthogonal computational cells. Nevertheless, the numerical results are sufficiently accurate, no matter which mesh type is applied.