The Linearized Potential Flow, Transient (lpft) interface (), found under the Acoustics>Aeroacoustics branch () when adding a physics interface, is used to compute the acoustic variations in the velocity potential in the presence of an inviscid and irrotational background mean flow, that is, a potential flow. The background flow can be modeled using The Compressible Potential Flow Interface. The physics interface is used for convected acoustic simulations that can be described by the linearized compressible potential flow equations.

When this physics interface is added, these default nodes are also added to the Model Builder — Linearized Potential Flow Model, Sound Hard Boundary (Wall), and Initial Values. For axisymmetric components 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 Linearized Potential Flow, Transient 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 lpft.

Enter the Maximum frequency to resolve in the model. The default frequency is set to 1000[Hz] but should be changed to reflect the frequency content of the sources used in the model. Select the Time stepping (method) as Fixed (preferred) the default and recommended or Free. The Free option is in general not recommended for wave problems. The generated solver will be adequate in most situations if the computational mesh also resolves the frequency content in the model. Note that any changes made to these settings (after the model is solved the first time) will only be reflected in the solver if Show Default Solver or Reset Solver to Defaults is selected in the study.