The Compressible Potential Flow (cpf) interface (), found under the Acoustics>Aeroacoustics branch (), is used to compute the velocity potential and density in a compressible potential flow model. Derived values include the associated pressure, velocity, and temperature in the flow. In a compressible potential flow model, the flow is assumed to be represented by an ideal barotropic, irrotational fluid at constant entropy, that is, the fluid is also inviscid. The physics interface is used for modeling the background mean flow used as input to The Linearized Potential Flow, Frequency Domain Interface or The Linearized Potential Flow, Transient Interface.

When this physics interface is added, these default nodes are also added to the Model Builder — Compressible Potential Flow, Slip Velocity, and Initial Values. For axisymmetric models an Axial Symmetry node is also added.

Then, from the Physics toolbar, add other nodes that implement, for example, boundary conditions and sources. You can also right-click Compressible Potential Flow to select physics features from the context menu.

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 cpf.

This physics interface defines two dependent variables (field), the Mean flow velocity potential Phi and the Density rho. The name can be changed but the names of fields and dependent variables must be unique within a model.

Select the discretization order for the Mean flow velocity potential and the Density dependent variables. The default is Quadratic for both.