Name: SpectraSim
Availability: InStock

Theory

At an excited inlet the plane mode carries an incoming wave $A e^{i\phi}$ , with the phase from Phase of the incident wave. Its power is given by equation (1).

For a single inlet the transmission loss is a ratio of powers and does not depend on $|A|$ .
With several inlets driven together, only the ratios of their amplitudes and their phases matter.
The pressure field on the model (Results, acoustic pressure) scales linearly with $|A|$ .

Equations

p_{inc} = |A|\,e^{i\phi}\,\psi_0\,e^{-ik z}, \qquad W_{in} = \frac{|A|^2 S}{2\rho c}

(1)

where	meaning	unit
$A$	Incident amplitude (this field)	Pa
$\phi$	Phase	rad
$\psi_0$	Plane mode of the port (uniform, unit mean square)	-
$S$	Port area	m²
$\rho, c$	Density and speed of sound at the port	kg/m³, m/s

Default and rule

Default: 1 Pa
Rule: 1 Pa.
Source: The incident-wave convention is that of the program's port formulation, in which the port modes are normalised to unit mean square; the formulation is verified on a straight duct. The plane-wave power is the standard result for a uniform medium without flow.

Valid range > 0

Values

Above 0. The value scales every pressure linearly; it does not change any TL or IL.

Theory

Equations

Default and rule

Valid range > 0

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