The phenomena considered in this section are much more complex as they associate multiphase fluid flow and hydro-mechanical coupling (cf. relevant sub-sections of Section 11.3.2) as well as temperature effects. All the features described in the preceding section are to be considered here, associated with some new points.
Heat diffusion has to be modelled. Temperature variation affects fluid flow, by a modification of the fluid specific weight or viscosity. Moreover, if the two fluids concerned are a liquid and a gas (e. g. water and air), then equilibrium between the phases has to be modelled: dry air — vapour equilibrium.
Heat transfer is governed not only by conduction but also by advection by the liquid and gas movements. Similarly, transfers of vapour and dry air in the gas phase are not only governed by diffusion and gradient of species density, but also by advection of the global gas movements.
In such an analysis, the total number of d. o.f. per node is 5 for a 2D problem: 2 displacements, 2 fluid pore pressures and the temperature.
