The Pair Acoustic–Thermoviscous Acoustic Boundary coupling () is used to couple a Thermoviscous Acoustics interface to a Pressure Acoustics interface (in both frequency and time domain) in an assembly geometry where identity pairs have been created. This includes both the FEM-based pressure acoustics interfaces and the BEM-based pressure acoustics interface. This allows the use of a nonconforming mesh at the acoustic-thermoviscous acoustic boundary. As the mesh requirements are different for the two, the computational mesh can take advantage of this when resolving the waves and the thermoviscous boundary layers, in this way saving degrees of freedom when solving.

This section defines the physics involved in the multiphysics coupling. The Acoustics and Thermoviscous Acoustics lists include all applicable physics interfaces. See the Coupled Interfaces in Acoustic–Structure Boundary for details.

When coupling on pairs with this feature it is recommended to use the Create imprints option in the final Form Assembly step in the Geometry sequence. Moreover make sure that the Allowed region is set to Nonpair region in the Applicable Pair Region section in the Wall feature. In all cases, check the selections of all features in the model.