The Fluid-Membrane Interaction, Fixed Geometry Interface
The Fluid-Membrane Interaction, Fixed Geometry () interface can be used to model phenomena where a fluid and a deformable membrane structure affect each other. Both the fluid loading on the structure and the structural velocity transmission to the fluid can be taken into account. The interface models situations where the displacements of the membrane are assumed to be small enough for the geometry of the fluid domain to be considered as fixed during the interaction.
You add a predefined Fluid-Membrane Interaction, Fixed Geometry interface from the Fluid-Structure Interaction () group in either the Structural Mechanics branch () or the Fluid Flow branch () of the Model Wizard or Add Physics windows. Laminar Flow and Membrane interfaces are then added to the Model Builder.
In addition, the Multiphysics node is added, which automatically includes the multiphysics coupling feature Fluid-Structure Interaction.
On the Constituent Physics Interfaces
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The Laminar Flow interface is described in The Single-Phase Flow, Laminar Flow Interface. When the CFD Module is available, turbulent flow is supported through the inclusion of a number of turbulence models.
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The Membrane interface is described in The Membrane Interface.
You can add a Stationary, One-Way FSI or Time Dependent, One-Way FSI studies. See Stationary and Time Dependent One-Way Studies for Fluid-Structure Interaction in the COMSOL Multiphysics Reference Manual for more information.
Settings for Physics Interfaces and Coupling Features
When physics interfaces are added using the predefined couplings, all specific settings are included with the physics interfaces and the coupling features.
However, if physics interfaces are added one at a time, followed by the coupling features, these modified settings are not automatically included.
For example, if single Laminar Flow and Membrane interfaces are added, COMSOL Multiphysics adds an empty Multiphysics node. You can choose from the available coupling features, but the modified settings are not included.
Coupling features are available from the context menu (right-click the Multiphysics node) or from the Physics toolbar, Multiphysics Couplings menu.
Physics Interfaces and Coupling Features
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.
Coupling Features
The Fluid-Structure Interaction, Fixed Geometry coupling feature is used to couple the interfaces.
Physics Interface Features
Physics nodes are available from the Physics ribbon toolbar (Windows users), Physics context menu (macOS 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.
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The available physics features for The Single-Phase Flow, Laminar Flow Interface are listed in the section Domain, Boundary, Pair, and Point Nodes for Single-Phase Flow in the COMSOL Multiphysics Reference Manual.
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The available physics features for The Membrane Interface are listed in the Boundary, Edge, Point, and Pair Nodes for the Membrane Interface section.