15.15. Radiation impedance
To derive the radiation impedance Z
AR
, we modify Eq. (13.212) from Section 13.10 for the uniform velocity distribution of a rigid piston to obtain that for one with a parabolic velocity distribution
(15.88)
and replace Eq. (13.215) with b(m
+
1)
=
2(−
δ
m0
+
δ
m1). By analyzing the low frequency asymptotic behavior, we obtain the radiation impedance elements