Physics-Controlled Mesh for Pressure Acoustics

When modeling acoustic problems using the Pressure Acoustics, Frequency Domain or the Pressure Acoustics, Transient interfaces the computational mesh can be automatically set up using the functionality. For these two physics, the generated computational mesh will follow best practices. The mesh will automatically resolve the wave, perfectly matched layer (PML) domains will have an appropriate mapped mesh, a boundary layer mesh is added for the exterior field, and periodic boundaries will be set up with copy mesh operations.

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First, select the as (the default) or , see Figure 2-7. When the user-controlled option is selected the mesh sequence nodes, generated by the physics, are shown and can be modified. For a fully user-defined mesh proceed and directly right-click the node, in the tree, and add the first desired mesh element. The physics that contribute to the physics-controlled mesh generation can be selected in the list.

Figure 2-7: User interface of the Physics-controlled mesh options for Pressure Acoustics as seen on the Mesh node.

Resolving the wave in space (see also Meshing: Resolving the Waves in Space) requires and input of the maximum frequency solved for in the model. The way the frequency is picked up and how many elements are used to resolve the wave, can be controlled in the physics-controlled mesh user interface, see Figure 2-7.

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Select the as (the default) or . For the default option, the maximum frequency will, for frequency domain problems, be picked up from the list in the frequency domain study step; while for time domain problems the value is picked up from the setting in the Transient Solver and Mesh Settings section. In the frequency domain case enter frequency values in the study step before generating the mesh. Alternatively select the option and manually enter the . The manual input can be a good option in models with several studies to ensure that the mesh is the same for all.

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Select the as (the default) or . The option gives 5 elements per wavelength.

The mesh also needs to resolve the geometry details in the model. The overall refinement such as minimum mesh size, maximum element growth rate, curvature factor, and the resolution of narrow region values are controlled by the option. The default is to use the setting.


	If a model contains a Parametric Sweep, the physics-controlled mesh will be regenerated for each new parameter value. This is of course important, if the parameter changes the geometry or the minimum wavelength in the model. For example, if a sweep is done over a number of frequency bands, a proper mesh should be regenerated for each band. In cases where the parameter has no influence on the mesh, remeshing will still take place, and may slow down the solution process. In this case it is advised to instead use an Auxiliary Sweep (an inner sweep) found in the Study Extensions section.

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Acoustic Scattering off an Ellipsoid. Application Library path

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Absorptive Muffler. Application Library path


	Meshing in the COMSOL Multiphysics Reference Manual