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Acoustic Tab (Transient Analysis)

Analysis conditions for the acoustic analysis (transient analysis) are set on this tab.

It is in the [Edit Boundary Condition] dialog box. See [How to Set Boundary Condition].

The boundary conditions that can be set for the transient analysis are listed below.

Boundary Condition Type	Notes
Displacement	Specifies the driving displacement. It can be used if the waveform is sine wave.
Velocity	Specifies the driving speed.
Acceleration	Specifies the driving acceleration. It can be used if the waveform is sine wave.
Pressure	Specifies the driving pressure.
Sound Pressure Level	Specifies the driving pressure by the sound pressure level [dB]. It can be used if the waveform is sine wave.
Acoustic Impedance	Specifies the acoustic impedance. The imaginary part cannot be set in the transient analysis.
Open Boundary	Applies to the infinite space where the sound waves travel without reflection.
Rigid Wall	Applies to the non-vibrating boundary.

The frequency dependency is selectable for the harmonic analysis only.

If pressure, displacement, speed, or acceleration are selected as a boundary condition type, the incident waveform must be set as these condition types are incident boundaries.

To check the waveform, press .

If the number of incident waves is specified, all waveforms will be displayed. If the number is not specified, the waveform of one period will be displayed.

Waveform Type		Notes
Type	Constant	The waveform of a certain size is constantly incident at all times.
	Sine wave	The incident waveform is the sine wave. The number of waves and the phase to start incidence can be specified.
	Square wave	The incident waveform is the square wave. The number of waves and the phase to start incidence can be specified.
	User to define	The user-defined incident waveform is applied. to be clicked to open a table for setting.
Waveform	Magnitude	Specifies the maximum value of the incident waveform. It can be specified if the waveform type is either constant, sine wave, or square wave.
	Phase	Specifies the phase to start the incidence. It can be specified if the waveform type is either sine wave or square wave to which the frequency can be set. For the phase Θ, the time to begin the incidence is Θ/(360*f ) [s] with reference to the frequency f [Hz].
	The number of incident waves	Specifies the number of incident waves. If it is not specified, the incidence is made at all times. It can be specified if the waveform type is either sine wave or square wave.
Frequency		Specifies the frequency for the incident wave. It can be specified if the waveform type is either sine wave or square wave.
Duty Cycle		Applicable if the waveform type is square wave. The duty cycle represents the ratio of the incidence in one period.