Dispersion in spatially periodic porous media

The method of volume averaging is applied to ordered and disordered spatially periodic porous media in two dimensions in order to compute the components of the dispersion tensor for low Peclet numbers ranging from 0.1 to 100. The effect of different parameters on the dispersion tensor is studied. The longitudinal dispersion coefficient decreases with an increase in disorder while the transverse dispersion coefficient increases. The location of discs in the unit cell influences the longitudinal dispersion coefficient significantly, compared to the transverse dispersion coefficient. Under a laminar flow regime, the dispersion coefficient is independent of Re-p. The predicted functional dependency of dispersion on the Peclet number agrees with experimental data. The predicted longitudinal dispersion coefficient in disordered porous media is smaller than that of the experimental data. However, the predicted transverse dispersion coefficient agrees with the experimental data.