Interior Lumped Speaker Boundary
The Interior Lumped Speaker Boundary is used to model a miniature loudspeaker (dust cap, cone, surround assembly, and motor) or another microtransducer using a lumped representation with a coupling to an Electrical Circuit interface. Add this node from the Interior Conditions submenu. The mechanical and electric properties of the speaker can, for example, be prescribed through a Thiele-Small representation and associated lumped parameters. The interior version of the Lumped Speaker Boundary includes the effects of the fluid domains on both sides of the speaker boundary explicitly. For time domain modeling including possible nonlinear lumped effects see the Lumped Speaker Boundary and Interior Lumped Speaker Boundary of The Thermoviscous Acoustics, Transient Interface.
When the Interior Lumped Speaker Boundary is placed next to a Wall or Interior Wall, with No slip as the Mechanical condition, it is necessary to exclude common points (in 2D axisymmetry) or common edges (in 3D). This is done in the Excluded Points/Edges section. To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box.
Speaker Geometry
Define how the Speaker area (projected) of the speaker is computed by selecting either Selected boundaries (the default) if all boundaries are present, or Use symmetries if the speaker surface is only partially represented.
When Use symmetries is selected, select the Speaker area multiplication factor Ascale as Automatic (the default, the model is analyzed for the presence of symmetry conditions); or User defined and enter a value (default is 1). The settings are required in order to compute the effective area of the speaker which is used to compute the acoustic load and radiated power.
Define the Speaker axis direction eax by selecting Automatic (the default) or User defined. For the automatic option the axis is computed as the average of the surface normals, this option is valid if a full speaker surface is selected. The User defined option should be used if the speaker surface is only partially represented and is the only option when Use symmetries is selected.
For the Automatic option select Reverse automatic speaker axis direction if necessary. The axis orientation can be visualized by plotting the axis components ta.ilsb1.e_axx, ta.ilsb1.e_axy, and ta.ilsb1.e_axz. (using the proper item and physics scope).
For the Circuit, Mechanical, Thermal, Constraint Settings, Exclude Edges, and Exclude Points sections see the Lumped Speaker Boundary.