Physics Region

Defines a distinct location in your simulation domain for which you define the type of physics that will be solved.

Acoustic Analyses

During an acoustic analysis, an Acoustics Region and/or a Structural Region object are automatically included in the Outline. Both of these objects are Physics Region objects. You use them to specify the geometry bodies that belong to the Structural or Acoustics physics type. All of the bodies must have a physics type associated via Physics Region objects.

Coupled Field Analyses

During a Coupled Field analysis, a Physics Region object is automatically included in the Outline. You use this object to specify the geometry bodies that belong to the Structural, Acoustics, Electric, Thermal or some supported combination of these types. All of the bodies must have a physics type specified by a Physics Region object.

Note:  The Show Coupled Physics Analysis setting, available in the Graphics category of the preferences dialog, enables you to display the bodies and/or parts associated with each properly defined Physics Region as a different color when the Environment object is selected.

Acoustics and Structural Region objects for a Static Acoustics analysis:

Object Properties

Tree Dependencies

Insertion Methods

Right-click Options

API Reference

Additional Related Information

Physics Region object for a Coupled Field Static analysis:

 

Object Properties

The Details Pane for this object includes the following properties.

CategoryProperties/Options/Descriptions

Scope

Scoping method: Specify as Geometry Selection (default) or Named Selection.

Geometry (Body selection only): Visible when the Scoping Method property is set to Geometry Selection. You use this property to specify the body or bodies belonging to structural or acoustic physics (using the properties below). Use the Body selection filter to pick your geometry, click in the Geometry field, and then click the Apply button that displays. After you select the geometry, this property displays the geometric entities (1 Body, 3 Bodies, etc.).
Named Selection: Visible when the Scoping Method property is set to Named Selection. This field provides a drop-down list of available user–defined (and body-based) Named Selections.

Definition

Structural: Specify the selected geometry or geometries as Structural. The default setting depends upon the analysis type.

Acoustics: Specify the selected geometry or geometries (solid bodies only) as Acoustic. The default setting depends upon the analysis type.

Thermal: Specify the selected geometry or geometries (solid bodies only) as Thermal for a coupled field analysis. The default setting is Yes.

Electric: Options include No, Charge, and Conduction. Specify the selected geometry or geometries as Electric. This property also specifies the formulation type, whether it is a charge-based formulation or current-based formulation. The default setting depends upon the analysis type.

Suppressed: Toggles suppression of the object. The default setting is No.

Coupling Options (Coupled Field Analyses Only)

Thermal Strain: This property is visible when the Thermal and Structural properties above are set to Yes. You use this property to specify the coupling method for a structural-thermal physics problem. Options include Program Controlled (default), Strong, and Weak. The setting of the Program Controlled option varies based on the selected physics as well as the selected solver.

  • During a Structural Thermal Electric Conduction analysis, the Program Controlled option uses the Strong setting. However, if you select the Iterative solver, the application uses the Weak setting.

  • During a Structural Thermal analysis, the Program Controlled option always uses the Strong setting.

Thermoelastic Damping: This property is visible for a Coupled Field Transient analysis when the Thermal and Structural properties above are set to Yes. Options include On and Off (default).

Piezoelectric: When the Structural property is set to Yes and the Electric property is set to Charge, this read-only property indicates that the selected region is a piezoelectric region. If the material assignment of any body scoped to the Physics Region includes a piezoelectric matrix, defined in the Engineering Data workspace, this property is activated and automatically set to On. Otherwise, it is set to Off.

Electrostatic Force: For a Coupled Field Static and Coupled Field Transient analyses when the Structural property is set to Yes and the Electric property is set to Charge, this property indicates that the selected region includes electrostatic structural coupling defined. It applies an electrostatic force to the scoped bodies based on the following options:

  • No (default): No electrostatic force is applied.

  • Applied To All Nodes: Electrostatic Force is applied to each element node.

  • Applied To Air Structure Interface (Symmetric): Electrostatic force is applied to the air-structure interface or to element nodes that have constrained structural degrees of freedom. This option produces a symmetric force coupling matrix by ignoring some of the terms associated with the nodes of the interior air domain. For this setting, Ansys recommends that you use a single layer low-order (no mid-side nodes) mesh of elastic air elements.

  • Applied To Air Structure Interface (Unsymmetric): Electrostatic force is applied to the air-structure interface or to element nodes that have constrained structural degrees of freedom. All terms of the force coupling matrix are retained, which produces an unsymmetric matrix. For this setting, Ansys recommends models that include multiple layers of elastic air elements.

Note:  These options are also available for static coupling when applied as an upstream system for a prestressed Coupled Field Harmonic analysis.

Acoustic Domain Definition (Visible for Acoustic Definition Only)

Artificially Matched Layers: Options include Off (default), PML, and Irregular PML. When you select PML or Irregular PML, a new PML Options category displays in the details view that enable you to define the PML options, as described below.

Important:  For a Static Acoustics analysis, if you activate this property, downstream Modal systems become invalid.

For additional information, see the Artificially Matched Layers section in the Mechanical APDL Acoustic Analysis Guide.

Element Morphing: Enables you to specify that the mesh for the bodies selected by the Acoustics Region can be updated, that is, morphed, due to any deflection of the Structural Region. Options include Program Controlled (default), Off, and On. The Yes setting specifies the mesh of the selected bodies is morphed and when Program Controlled, the setting considers the following:

  • If the Large Deflection property is set to Off, the KEYOPT for the MORPH command is deactivated.

  • If the Large Deflection property is set to On, the KEYOPT for the MORPH command is activated for acoustic bodies connected to structural bodies. This also requires that (1) the Artificially Matched Layers property is not active, (2) the body is not connected to absorbing elements or contact conditions.

Note:  Acoustic elements do not affect a Static Acoustics analysis other than for a morphed mesh.

Piezoelectric Domain Definition (Visible for Piezoelectric Coupling in Coupled Field Harmonic analyses)

Perfectly Matched Layers: Options include Off (default) and PML. When you select PML, and Options category displays in the Details that enables you to define the PML Options properties, as described below.

Structural Domain Definition (Visible only when the Structural physics property set to Yes in Coupled Field Harmonic analysis)

Perfectly Matched Layers: Options include Off (default) and PML. When you select PML, and Options category displays in the Details that enables you to define the PML Options properties, as described below.

PML Options (Visible when Artificially Matched Layers or Perfectly Matched Layers property is set to PML)

PML Element Coordinate System: The Global Coordinate System is the default setting.

PML Options: Options include 3D PML (default) and 1D PML.

Reflection Coefficients: Options include Program Controlled (default) and Manual. When this property is set to Manual, the following additional properties display based upon the setting of the PML Options property, either:

3D PML Setting 1D PML Setting

--Value in -X Direction

-- Value

--Value in +X Direction

 

-- Value in -Y Direction

 

-- Value in +Y Direction

 

-- Value in -Z Direction

 

-- Value in +Z Direction

 

Evanescent Wave Attenuation: Options include No (default) and Yes.

For additional information, see the Perfectly Matched Layers (PML) section in the Mechanical APDL Acoustic Analysis Guide.

Irregular PML (Visible for Acoustic analyses when Artificially Matched Layers property set to Irregular PML)

Reflection Coefficients

Evanescent Wave Attenuation: Options include No (default) and Yes.

For additional information, see the Irregular Perfectly Matched Layers (IPML) section in the Mechanical APDL Acoustic Analysis Guide.

Advanced (Visible for Acoustic Definition Only)

Reference Pressure: Enter a Reference Pressure value. The default value is 2e-5 Pa.

Reference Static Pressure: Enter a Reference Static Pressure value. The default value is 101325 Pa.

Fluid Behavior: Specify the compressibility of the fluid. Available options are Compressible (default) or Incompressible.

Tree Dependencies

  • Valid Parent Tree Object: The Environment object is the only valid parent object.

  • Valid Child Tree Objects: No current child objects are supported for this object.

Insertion Methods

This object is automatically inserted into the Outline when you open the analysis type in Mechanical. Additional objects can be inserted. Select the analysis's environment object, and:

  • Right-mouse click and select Insert > Physics Region.

    Or...

  • Select the Physics Region option on the Evironment Context tab.

Right-click Options

In addition to common right-click options, relevant right-click options for this object include:

Note:  See the associated analysis type section for the supported loads for each analysis type.

Note:  For more detailed information about setting the Acoustic Domain Definition and Acoustic FSI Definition, see the Elements for Acoustic Analysis section of the Mechanical APDL Element Reference.

API Reference

See the Physics Region section of the ACT API Reference Guide for specific scripting information.

Additional Related Information

For more information on acoustic domain definition and FSI definition properties, refer to Elements for Acoustic Analysis section in the Mechanical APDL Element Reference