In FLUENT 6.1, the surface reaction capabilities have been enhanced. Multi-step reactions, multiple sites and site species can be handled, enabling more accurate modeling of complex surface chemistry, including deposition and etching. The porous media model has also been enhanced to better handle chemically reacting flows, typical of packed bed reactors. Surface reactions can now be included in porous zones. The actual physical velocities in porous media can be computed in order to account for the effects of fluid acceleration in the catalyst regions.

Contours of the deposition rate of gallium arsenide along with the flow pathlines are shown for a rotating disk MOCVD reactor. Courtesy of EMCORE Corporation

Different chemical reactions can be solved in individual zones and can even be disabled in certain zones, if desired. This is helpful for modeling reactors that contain catalyst regions.

Also new in FLUENT 6.1 is the composition PDF transport model, implemented through a collaboration with Professor Stephen Pope of Cornell. It provides an accurate turbulence-chemistry interaction model for real finite-rate chemistry in turbulent flames. Finite rate chemistry is needed to capture non-equilibrium phenomena such as ignition, extinction, and slow species (e.g., CO). : In addition, speed-ups of two to three orders of magnitude can be achieved when in-situ adaptive tabulation (ISAT) is used for turbulent finite rate chemistry simulations with either the PDF transport model or the eddy dissipation concept (EDC) model.

Temperature contours in a trapped vortex combustor, simulated with the PDF transport model.
Courtesy of NETL