Interior problem

The sound wave oscillates in an enclosure or propagates to the infinity in a constrained structure.

Exterior problem

The sound wave radiates or is scattered into the infinite open space.

FSI

Acoustic fluid-structure interaction.

Coupled element

Acoustic element with FSI interface.

Uncoupled element

Acoustic element without FSI interface.

PML

Perfectly matched layers.

IPML

Irregular perfectly matched layers.

Sound-hard surface

A surface on which particle normal velocity is zero. The sound-hard surface is also referred to as the rigid wall, which is the default boundary condition.

Sound-soft surface

A surface on which sound pressure is constrained.

Transparent port

An exterior surface on which incident pressure is launched into the acoustic model and the reflected pressure wave is fully absorbed by a defined matched impedance that represents the infinity.

Vibro port

An exterior surface on which incident pressure is launched into the acoustic model by the vibration of the structural surface.