Thermal and dielectric behavior of porous media
Understanding the heat transfer and electromagnetic (EM) porous media behavior is vital in conducting analysis and modeling operations in various fields of geomechanics and geotechnics. Furthermore, the thermal and dielectric processes of porous media are highly correlated and are both affected by changes in similar hydro-mechanical parameters. In this thesis, relationships between the effective thermal conductivity and effective complex dielectric permittivity of soils and oil sands, were experimentally studied using thermal and high frequency electromagnetic (HF-EM) measurement techniques, and as expected, a strong correlation between the two parameters was obtained for a wide range of hydro-mechanical conditions. Additionally, semi-theoretical models for the prediction of the effective thermal conductivity of soils and oil sands as a function of effective complex dielectric permittivity were proposed. The new models can be used to estimate the effective thermal conductivity of large scale sub-surface porous media deposits using dielectric data collected from non-destructive HF-EM measurement techniques such as the ground penetrating radar (GPR), without the need to extract samples for moisture and/or bitumen content measurement. Moreover, the findings of the experimental and theoretical studies were further corroborated with the development of a new numerical lattice element method (LEM) based model, which can accurately predict the magnitudes of the effective thermal conductivity and effective complex dielectric permittivity as well as their local spatial distributions in porous media domains.
Use and reproduction:
No license. The provisions of the German Copyright Act (UrhG) apply.