The Reacting Pipe Flow Interface
The Reacting Pipe Flow (rpfl) interface (), found under the Chemical Species Transport branch () when adding a physics interface, is a multiphysics interface that combines the three physics interfaces: Pipe Flow, Heat Transfer in Pipes, and Transport of Diluted Species in Pipes. The physics interface approximates the flow profiles in pipes and channels by a 1D assumption on lines in 2D and 3D. Depending on additional add-on products, multiple species can be modeled.
When this physics interface is added, these default nodes are also added to the Model BuilderFluid, Pipe Properties, Temperature, Pressure, Concentration, and Initial Values. Then, from the Physics toolbar, add other nodes that implement, for example, boundary conditions and volume forces. You can also right-click Reacting Pipe Flow to select physics features from the context menu.
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 rpfl.
Fluid Model
Select a Fluid modelNewtonian (the default), Power law, or Bingham.
Physical Model
Enter a Reference pressure level pref (SI unit: Pa). The default value is 1[atm].
Dependent Variables
This physics interface defines these dependent variables (fields). If required, edit the name, but dependent variables must be unique within a model:
Pressure p (SI unit: Pa)
Tangential velocity u (SI unit: m/s)
Temperature T (SI unit: K)
Concentration c (SI unit: mol/m3)
Discretization
Use this section to change the discretization order for the dependent variables.