The local thermal nonequilibrium hypothesis describes heat transfer in a porous medium using two temperature fields to solve: Tf for the fluid phase and
Ts for the porous matrix. These should satisfy the following couple of partial differential equations:
The Local Thermal Nonequilibrium multiphysics coupling feature combines two actions in order to couple the two aforementioned physics interfaces. It first multiplies each energy equation by its volume fraction:
θp and
(1 − θp) for solid and fluid phases, respectively. Then it adds the heat exchange term
±qsf(Tf − Ts) in both equations.
As shown in Equation 4-129 and
Equation 4-130, the volumetric heat sources
θpQs and
(1 − θp)Qf are applied to the energy equations. The
Heat Source features of each physics interface though specifies
Qs and
Qf. Special care is therefore needed when defining a heat source for the whole porous medium. You would have to ensure that the heat source densities,
Qs and
Qf, are both equal to the heat rate density that was intended to the porous medium.