The Reacting Flow in Packed Beds, Transport of Diluted Species with Shrinking Core Model interface () is used to model a reactor filled with initially solid reactant particles. As the reactant particles are consumed by heterogeneous reactions, occurring on the core surface, the solid core shrinks leaving a porous layer around it. Apart from the core consuming reactions, transport and reactions inside the porous reacted layer, as well as transport in the pore space around the particles can be studied in detail.

It combines the Brinkman Equations interface (), and a Transport of Diluted Species in Packed Beds interface (). The Reacting Flow, Diluted Species multiphysics coupling, which is added automatically, couples fluid flow and mass transport. A Porous Material node, including a Fluid and a Solid subnode, is also added to the component.

The Brinkman Equations interface computes the fluid velocity and pressure fields of single-phase flow in porous media in the laminar flow regime. A Porous Medium feature is active by default on the entire interface selection.

The Transport of Diluted Species in Packed Beds interface solves for the concentration of an arbitrary number of bulk species, and optionally, an arbitrary number of surface species in porous pellets. The bulk species are assumed to be solutes, dissolved in a solvent of significantly higher concentration. In the current multiphysics interface a Packed Bed feature, using the Shrinking Core Model, is active by default on the entire interface selection.