Radiation Impedance - Circular Unflanged Opening
R2026bRadiation Impedance - Circular Unflanged Opening block
To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.
Libraries:
Simscape Acoustics /
Radiation Impedance
Description
Add-On Required: This feature requires the Simscape Acoustics add-on.
The Radiation Impedance - Circular Unflanged Opening block models the radiation impedance from an unflanged circular opening. An unflanged circular opening behaves similarly to the Spherical Source Radiation Impedance, with slight differences. For very low frequencies, the component acts like a mass loading, represented as an inertance with value
where:
Bi is the end correction coefficient of the opening.
ρ is the density of the fluid.
r is the radius of the opening.
A is the surface area of a sphere with the same radius as the opening.
For very high frequencies, the block acts like a pure resistive damping, represented as a resistance with value
where:
Br is the proportion of impedance corresponding to radiated power.
c is the speed of sound in the fluid.
For unflanged openings, Bi = 0.61 and Br = 0.25 [1].
Ports
Conserving
Parameters
References
[1] Beranek, Leo Leroy, and Tim J. Mellow. Acoustics: Sound Fields, Transducers and Vibration. Second edition. Academic Press, 2019.
Version History
Introduced in R2026b
