3.2.4.6. Radiation Transport Equation

The transport of radiative intensity in a given direction $I(s)$ through an absorbing medium is governed by the radiation transport equation.

(3.27) $s \cdot \grad I(s) + \mu_a I(s) = S$

Where $s_i$ is an ordinate direction, $\mu_a$ is the absorption cross section, and $S$ is the radiation source. Note that Aria currently does not support scattering terms for the radiation transport equation, so they have not been included here.

The radiation transport equation is not solved in Aria, but rather through an MPMD coupling to a PMR application. An MPMD coupling block in the Aria region is required to activate this equation (see MPMD Coupling). The only valid term for this equation is XFER, and this equation specification is simply used to activate the MPMD coupling for the selected mesh part.