When you are simulating applications that can be described by the material transport interfaces in the Chemical Species Transport branch, there is often a need to couple the material transport to other physics interfaces. Convection is often the cause of the material transport, so couplings to Fluid Flow interfaces is required. The CFD Module includes physics interfaces for Laminar Flow and Porous Media Flow as well as more advanced descriptions of fluid flow, such as turbulent and Multiphase Flow.