The Thermoviscous Acoustic-Shell Interaction, Frequency Domain Interface
This physics interface requires a Structural Mechanics Module license. For theory and physics interface feature descriptions relating to the Shell interface, see the Structural Mechanics Module User’s Guide.
The Thermoviscous Acoustic-Shell Interaction, Frequency Domain multiphysics interface (), found under the Acoustics>Thermoviscous Acoustics branch () when adding a physics interface, combines the Thermoviscous Acoustics, Frequency Domain and Shell interfaces. The physics interface solves for and has a predefined coupling between the displacement field of the shell and the acoustic variations in the fluid domains. It can be used, for example, for modeling the vibrating response of micromirrors in MEMS applications. The physics interface is available for 3D and 2D axisymmetric geometries, and it is capable of modeling the coupled thermoviscous acoustics and shell vibrations in the frequency domain.
The physics interface solves the equations in the frequency domain assuming all fields and sources to be harmonic. Linear acoustics is assumed.
When a predefined Thermoviscous Acoustic-Shell Interaction, Frequency Domain interface is added from the Acoustics>Thermoviscous Acoustics branch of the Model Wizard or the Add Physics windows, the Thermoviscous Acoustics, Frequency Domain and Shell interfaces are added to the Model Builder.
In addition, the Multiphysics node is added, which automatically includes the multiphysics coupling Thermoviscous Acoustic-Structure Boundary. This multiphysics coupling automatically couples the thermoviscous acoustic domain to exterior shells (on exterior boundaries) and to interior shells (on interior boundaries).
For details about all the multiphysics couplings in the Acoustics Module, see Multiphysics Couplings.
Settings for Physics Interfaces and Multiphysics Couplings
When a predefined multiphysics interface is used, for example Thermoviscous Acoustic-Shell Interaction, Frequency Domain, the Selection on the multiphysics coupling is automatically set to All boundaries. In this way, the multiphysics coupling is automatically active on all boundaries with Thermoviscous Acoustics, Frequency Domain on one side (exterior shells) or on both sides (interior shells) of Shell boundaries.
However, if physics interfaces are added one at a time, followed by the multiphysics couplings, these modified settings are not automatically included.
For example, if the single interfaces are added, COMSOL adds an empty Multiphysics node. You can choose the available multiphysics couplings, but you need to manually select on which boundaries they need to be applied, or select All boundaries to recover the predefined behavior.
Multiphysics couplings are available from the context menu (right-click the Multiphysics node) or from the Physics toolbar, Multiphysics menu.
Physics Interfaces and Multiphysics Couplings
Use the online help in COMSOL Multiphysics to locate and search all the documentation. All these links also work directly in COMSOL Multiphysics when using the Help system.
Multiphysics Coupling
See Thermoviscous Acoustic-Structure Boundary in the Multiphysics Couplings chapter.
Physics Interface Features
Physics nodes are available from the Physics ribbon toolbar (Windows users), Physics context menu (Mac or Linux users), or right-click to access the context menu (all users).
In general, to add a node, go to the Physics toolbar, no matter what operating system you are using. Subnodes are available by clicking the parent node and selecting it from the Attributes menu.
•
The available physics features for The Thermoviscous Acoustics, Frequency Domain Interface are listed in the section Domain, Boundary, and Pair Nodes for the Thermoviscous Acoustics, Frequency Domain Interface.
•
The available physics features for Results Evaluation are listed in the section Domain, Boundary, Edge, Point, and Pair Nodes for the Shell and Plate Interfaces in the Structural Mechanics Module User’s Guide
•
Theory Background for the Thermoviscous Acoustics Branch
•
Theory for the Shell and Plate Interfaces in the Structural Mechanics Module User’s Guide