Acoustic Impedance (Isentropic)
The Acoustic Impedance (Isentropic) adds a simple acoustic impedance assuming isentropic (adiabatic) behavior for the fields. This condition should be used with care as it is not necessary that the solution is isentropic near a boundary. The Ingard-Myers type impedance condition is defined by the Impedance and Interior Impedance conditions. The isentropic impedance conditions reads:
In transient models, use this boundary condition in combination with the Absorbing Layers for the Linearized Euler, Transient Interface to create efficient nonreflection conditions.
Impedance
Enter an expression or value for the Impedance Zi (SI unit: Pa·s/m). The default value is set to let.rho0*let.c0, which is the specific characteristic impedance of a plane propagating wave.
Constraint Settings
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Excluded Edges/Points
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box. See Suppressing Constraints on Lower Dimensions for details.