It is critical to emphasize that in the experimental setup of interest, the concentration profiles are strongly affected by the details of the 3D geometry of the system. When the geometry is approximated by a 1D or a 2D reduced description, the results are significantly different from those obtained via 3D modelling. The computational domain of interest was simplified and discretized by 5.8 × 10 lattice grid points. More specifically, it was represented by a 3D lattice with the dimension of 1500 × 62 × 62, as shown in Figure , with each voxel representing a spatial resolution of 0.05 mm. To ensure second-order accuracy for the solid boundary condition, which involves handling the interface where the fluid transport simulation interacts with the solid structures of the experimental setup, the half-way bounce-back boundary was implemented . This approach is essential for accurately modeling how the diffusing substances interact with solid surfaces, ensuring that the diffusion dynamics are properly captured, which is critical for the accuracy of the simulation results.