The Specific 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 conditions. The isentropic specific acoustic impedance conditions reads:
Enter an expression or value for the Specific impedance Zn (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.
) and select Advanced Physics Options in the Show More Options dialog box.
) and select Advanced Physics Options in the Show More Options dialog box. See Suppressing Constraints on Lower Dimensions for details.