Fully coupled thermo-hydro-mechanical analysis by an algebraic multigrid method

In this paper, an algebraic multigrid method is suggested for the fully coupled thermo- hydro-mechanical analysis in deforming porous media. The mathematical model consists of balance equations of mass, linear momentum and energy and of the appropriate constitutive equations. The chosen macroscopic field variables are temperature, capillary pressure, gas pressure and displacement. The gas phase is considered to be an ideal gas composed of dry air and vapour, which are regarded as two miscible species. Phase change as well as heat transfer through conduction and convection and latent heat transfer (evaporation-condensation) are taken into account. The problem hence presents an interaction problem between several fields with very different response characteristics. Further, the matrices are non-symmetric and not diagonally dominated. Numerical examples are given to demonstrate the efficiency of this method.