The Poroelastic Waves Interface
The Poroelastic Waves (pelw) interface (), found under the Acoustics>Elastic Waves branch () when adding a physics interface, is used to compute the displacement field and acoustic pressure fluctuation in porous materials with propagating poroelastic waves. Dedicated Multiphysics Couplings exist that define the couplings between fluid, solid, and porous domains.
Examples of applications include the propagation of elastic waves in rocks and soils, modeling the acoustic attenuation properties of particulate filters, characterizing sound absorbers and liners, or modeling the porous foams in headphones. The physics interface is valid for modeling the propagation of the coupled linear elastic and linear acoustic waves in the frequency domain. Harmonic variations of the displacement field and the sources are assumed. In the porous domains, Biot’s equations are solved accounting for the coupled propagation of elastic waves in the elastic porous matrix and pressure waves in the saturating pore fluid. This includes the damping effect of the pore fluid due to viscous losses only (the Biot model), typically with a saturating liquid like water or oil, or the combined effect of viscous and thermal losses (the Biot-Allard model), typically when the saturating fluid is air.
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For information about modeling strategies and meshing see Meshing Poroelastic Waves Models and Solving Large Poroelastic Wave Models in the Modeling with the Elastic Waves Branch section.
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See the Theory for the Poroelastic Waves Interfaces for details about the governing equations. The specifics of the Biot and the Biot-Allard models are also discussed here.
When the Poroelastic Waves interface is added, these default nodes are also added to the Model Builder: Poroelastic Material, Porous, Free, and Initial Values. For 2D 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 Poroelastic Waves to select physics features from the context menu.
Settings
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 pelw.
The rest of the physics interface settings are the same as for The Pressure Acoustics, Frequency Domain Interface and The Solid Mechanics Interface.
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Acoustics of a Particulate-Filter-Like System: Application Library path Acoustics_Module/Automotive/acoustics_particulate_filter
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Acoustic Reflections off a Water-Sediment Interface: Application Library path Acoustics_Module/Underwater_Acoustics/reflections_water_sediment
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Headphone on an Artificial Ear: Application Library path Acoustics_Module/Electroacoustic_Transducers/headphone_artificial_ear