The Thermoviscous Acoustic SLNS-Structure Boundary coupling () is used to couple a Thermoviscous Acoustics, SLNS Approximation interface to any structural component. The feature couples to the Solid Mechanics, Shell, Layered Shell, Membrane, and Multibody Dynamics interfaces.

The coupling includes the fluid load on the structure and the structural acceleration as experienced by the fluid. For thin interior structures like shells or membranes with fluid on both sides, a slit is added to the pressure variable and care is taken to couple the up and down sides. This is done as for the Acoustic–Structure Boundary. The multiphysics coupling also sets up all relevant conditions for the viscous scaling function Ψv and the thermal scaling function Ψth, on the boundary.

See Settings for further details about Label and Name.

The default Name (for the first multiphysics coupling feature in the model) is tssb1.

This section defines the physics involved in the multiphysics coupling. The Acoustics and Structure lists include all applicable physics interfaces.

Select the Mechanical condition as No slip or Slip (perfect) (the default). The default for this multiphysics coupling is Slip (perfect), which gives a model with no viscous boundary layer on the coupled wall. For models with geometric dimensions comparable to the viscous boundary layer thickness use the no-slip option. For No slip, the formulation — used in the SLNS formulation for thermoviscous acoustics — can result in a solution that looks unphysical near the moving wall. However, these artifacts are only local effects that do not influence the overall results.

Select the Thermal condition as Isothermal or Adiabatic (the default).

These settings are shown when the Advanced Physics Options is selected. It controls how the constraints are handled.