3.14. Radiation Boundary

The Radiation Boundary boundary condition enables you to dampen the effect of sound pressure on the impedance boundary as well as to approximate infinity.

Analysis Types

The Radiation Boundary loading condition is available for Coupled Field Harmonic, Coupled Field Modal, Coupled Field Transient, Harmonic Acoustics, and Modal Acoustics analyses.

Dimensional Types

The Radiation Boundary loading condition is only supported for 3D simulations.

Geometry Types

Geometry types supported for the Radiation Boundary boundary condition are limited to Solid geometry only.

Topology Selection Options

The Radiation Boundary condition only supports Face selection.

Boundary Condition Application

To apply a Radiation Boundary:

  1. On the Environment Context tab: click Acoustic Boundary Conditions>Radiation Boundary. Or, right-click the Environment tree object or in the Geometry window and select Insert>Acoustics>Radiation Boundary.

  2. Define the Scoping Method.

Details View Properties

The selections available in the Details view are described below.

CategoryFields/Options/Description
Scope

Scoping Method, options include:

  • Geometry Selection: Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools.

    • Geometry (Face selection only): Visible when the Scoping Method property is set to Geometry Selection. Geometry selections must be made on bodies specified in the acoustic Physics Region.

      Use the Face 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 Face, 3 Faces, etc.).

  • Named Selection: Indicates that the geometry selection is defined by a Named Selection.

    • Named Selection: Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections (face-based only).

Definition

Type: Read-only field that describes the object - Radiation Boundary.

Suppressed: Include (No - default) or exclude (Yes) the boundary condition.

Mechanical APDL References and Notes

This boundary condition is applied using the INF label of SF command. Refer to the Surface Impedance Boundary section in the Mechanical APDL Acoustic Analysis Guide for more information.

API Reference

See the Radiation Boundary section of the ACT API Reference Guide for specific scripting information.