3.1. Mass Source

A Mass Source excitation is used to create a sound wave.

Analysis Types

The Mass Source excitation is available for Coupled Field Harmonic and Harmonic Acoustics analyses.

Common Characteristics

This section describes the characteristics of the excitation, including the application requirements, support limitations, and loading definitions and values.

Types Supported

  • 3D Simulation: Supported.

  • 2D Simulation: Not Supported.

Geometry Types: Geometry types supported for the Mass Source excitation include:

  • Solid: Supported.

  • Surface/Shell: Not Supported.

  • Wire Body/Line Body/Beam: Not Supported.

Topology: The following topology selection options are supported for Mass Source.

  • Body: Supported.

  • Face: Supported.

  • Edge: Supported.

  • Vertex: Supported.

  • Nodes: Not Supported.

  • Element Face: Not Supported.

  • Element: Not Supported.

Loading Types: The Mass Source boundary condition’s loading is defined by Magnitude only.

Loading Data Definition: Enter loading data using one of the following options.

  • Constant

  • Tabular (Frequency Varying)

Boundary Condition Application

To apply a Mass Source:

  1. On the Environment Context tab: click Acoustic Excitations>Mass Source. Or, right-click the Environment tree object or in the Geometry window and select Insert>Acoustic>Mass Source.

  2. Define the Scoping Method. Options include Geometry Selection (default) and Named Selection. For either scoping type, you must use the Body selection filter (on the Graphics Toolbar) for geometry selection or Named Selection definition. Only bodies specified in the acoustics Physics Region(s) can be selected or defined.

  3. Define the Magnitude.

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: 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 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: 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.

Definition

Type: Read-only field that describes the object - Mass Source.

Magnitude

Important:  Changing the geometry scoping may change the Unit system used for the Magnitude. For example, the Unit system for the Magnitude of a Face is kg/mm2 × s whereas the Unit for an Edge selection is kg/mm × s.

Phase Angle

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

Mechanical APDL References and Notes

Acoustic Mass Source is applied using the MASS label of BF command.

API Reference

See the Mass Source section of the ACT API Reference Guide for specific scripting information.