Numerical simulation for tortuosity of porous media

Tortuosity is used as an important parameter in the field of soil permeability and diffusion. Assessment of the earlier literature indicated a intimate relationship between tortuosity and porosity. Based on the deduction of double-scale asymptotic theory, we used the homogenization method and a numerical tool to calculate the effective diffusion coefficient and the tortuosity of a two-dimensional, representative elementary volume (REV) of circular particles. Then, through numerical calculation of different values of tortuosity, we have found that a general model before has the best fitting degree. However, the coefficients in the model were different, and they should be modified depending on the hygroscopicities of different materials. The proposed general formulation was evaluated by comparing it with available formulations and experimental data, and good agreement was found.

Tortuosity is used as an important parameter in the field of soil permeability and diffusion. Assessment of the earlier literature indicated that there are many relationships between tortuosity and porosity. Based on the deduction of double-scale asymptotic theory, we used the homogenization method and a numerical tool to calculate the effective diffusion coefficient and the tortuosity of a two-dimensional, representative elementary volume (REV) of circular particles. Then, through numerical calculation of different values of tortuosity, we have found that a general model before has the best fitting degree. However, the coefficients in the model were different, and they should be modified depending on the hygroscopicities of different materials. In the figure, general models with different amount of hygroscopic water are compared with the tortuosity of different kinds of porous media.Figure optionsDownload as PowerPoint slideHighlights
► We use the homogenization method to calculate the effective diffusion coefficient and the tortuosity of porous media.
► We choose a simple 2D unit cell with a circular particle to simulate the actual porous media.
► Through the numerical calculation, we have found that a general model before has the best fitting degree.
► The coefficients in the model of soils are different, which should be modified depending on the hygroscopicities.
► High adsorption capacity makes the values of tortuosity calculated more different from those measured.