The Chemistry Interface
This physics interface can be used to create reaction kinetics and optionally compute mass transport and thermodynamic properties for direct use in 1D, 2D, or 3D models. This is similar to The Reaction Engineering Interface, except that it does not solve for an ideal reactor model.
The Chemistry (chem) interface () is found under the Chemical Species Transport branch () when adding a physics interface. The Chemistry interface is also created when the Generate Space-Dependent Model feature is used in the Reaction Engineering interface, collecting all mixture variables and properties for use in a space-dependent model.
This physics interface is a tool for generating a set of variables to be used for modeling chemical species and reactions systems. The variables are generated from species and reaction properties and can be divided in two categories:
Many of the fields and nodes described in this section are only made available when either a Reaction or a Species (or both) subnode is added to the Model Builder. All predefined constants and expressions can be overwritten by user-defined expressions. This makes it possible to go beyond the modeling assumptions set as defaults in this physics interface.
The following is a description of the features and fields available in the Settings window for the Chemistry interface.
Settings
The Label is the default physics interface name.
The Name is used primarily as a scope prefix for variables defined by the physics interface. Refer to such physics interface variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the Name field. The first character must be a letter.
The default Name (for the first physics interface in the model) is chem.
Model Input
This section sets the Temperature, Pressure, and Electrode potential (only available with a Battery Design Module, Corrosion Module, Electrochemistry Module, Electrodeposition Module, or Fuel Cell & Electrolyzer Module license) to be used by the current interface. Use the lists to select a temperature, pressure, or electrode potential defined and announced by another interface in the model. For example, when a heat transfer interface is also included, the temperature solved for is available in the Temperature list.
For Temperature or Pressure, you can also select Common model input to use a globally available common model input. In all three cases, select User defined to manually define the variable in question.