Project description: COMSOL CAPE-OPEN Thermodynamic and Physical Properties interface

COMSOL are leaders in the simulation of reacting systems involving heat and mass transfer, and fluid dynamics. Specifically, they have a product that studies the chemical kinetics of such systems, as well as another that simulates such systems’ space and time-dependencies in 1D, 2D, 2D axisymmetry and 3D:

• The COMSOL Reaction Engineering Lab®: This creates models of reacting systems from user-inputted or imported thermodynamic and reaction kinetics data. It solves the material and energy balances for such systems, while further allowing you to run nonlinear parameter estimation on multiple sets of experimental data
• The Chemical Engineering Module: this easily couples transport phenomena—computational fluid dynamics (CFD), and mass and energy transport—to chemical reaction kinetics to model space-dependent reacting systems and chemical reactors

COMSOL version 3.5 will feature a CAPE-OPEN thermodynamic and physical properties interface, enabling COMSOL products to access property calculations from CAPE-OPEN compliant physical property packages. This will allow increased accuracy in models based around the physics of flow, heat and mass transfer, where they can also include chemical reaction kinetics.

Extending COMSOL’s existing ability to import data using the CHEMKIN® file format, the CAPE-OPEN thermodynamic and physical properties interface will support both CAPE-OPEN Thermo 1.1 and CAPE-OPEN Thermo 1.0 standards. External property packages are accessed through COMSOL Script®, which allows for compound constant import, single-phase, two-phase, pressure-dependent, and temperature-dependent property calculations, as well as for equilibrium computations. From COMSOL Script, you select the appropriate property package, set up the function object for desired property calculations and then evaluate this.

Such evaluations can subsequently be directly imported to the graphical user interfaces of COMSOL Multiphysics, the Chemical Engineering Module and COMSOL Reaction Engineering Lab. Here they are then explicitly incorporated into the equations for the solution of momentum, mass and energy balances to provide space-dependent models of reacting systems.

The reactor model presented here exemplifies the use of the new interface. It treats a three-dimensional steam reforming reactor where fluid flow, temperature, and composition are simulated for time and space dependency.

The simulation of a steam reformer using the COMSOL CAPE-OPEN thermodynamic and physical properties interface. From COMSOL Script, you select the appropriate property package, set up the function object for the desired property calculation and then evaluate this. Using the capeeval command directly in the COMSOL Multiphysics GUI, you solve the model using external thermodynamic and physical property calculations. The 3D figure shows the concentration of the product (slice plot), the temperature profile in the heating tubes and the direction and magnitude of the fluid flow (arrow plot) in the steam reformer.