Small Cylindrical Orifice or Tube

R2026b

Acoustic propagation in a small, cylindrical orifice

Since R2026b

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  • Small Cylindrical Orifice or Tube block

Libraries:
Simscape Acoustics / Applications / Tubes and Horns

Description

Add-On Required: This feature requires the Simscape Acoustics add-on.

This block models either a small orifice on a wall or baffle, or a short length of tube. The orifice is modeled as a mass, represented by an acoustic inertance, and a viscous loss, represented by an acoustic resistance. The inertance and resistance are connected in series.

Equivalent circuit to the Small Cylindrical Orifice or Tube block as a Simscape model.

The inertance value is modeled as

Ma=4ρL3A,

where:

  • ρ is the density of the fluid.

  • L is the length of the orifice.

  • A is the cross sectional area of the orifice [1].

The resistance value is modeled as

Ra=8πρμLA2,

where μ is the kinematic viscosity of the fluid [1].

If multiple orifices with the identical dimension are present, Ma and Ra are divided by N, the number of orifices.

Examples

New
Condenser Microphone Modeling with Simscape Acoustics

Condenser Microphone Modeling with Simscape Acoustics

Model a conventional condenser microphone using Simscape™ Acoustics.

Ports

Conserving

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Acoustic conserving port associated with the positive terminal.

Acoustic conserving port associated with the negative terminal.

Parameters

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Length of the wall, baffle, or tube in meters.

Radius of the orifice or tube opening in meters.

Number of holes/tubes, specified as a positive integer.

References

[1] Esteves, Josué, Libor Rufer, Didace Ekeom, and Skandar Basrour. “Lumped-Parameters Equivalent Circuit for Condenser Microphones Modeling.” The Journal of the Acoustical Society of America 142, no. 4 (2017): 2121–32. https://doi.org/10.1121/1.5006905.

Version History

Introduced in R2026b

See Also

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