4.21. Plane circular piston radiating from one side only in free space

The specific impedance (N·s/m3) of the air load on a plane piston in free space, which has one surface vibrating sinusoidally while the other remains stationary, is given by Eqs. (13.254) and (13.255) and plotted in Fig. 4.39.

Table 4.5

Radiation impedance and admittance for one side of a plane circular piston in free space a .
Impedance Mechanical Specific Acoustic Analogous circuits
f   =   drop
u   =   flow
p   =   drop
u   =   flow
p   =   drop
U   =   flow
ka < 0.5:
Series resistance, R
Series resistance, R
Mass, M 1
Compliance, C 1 ka > 5:
Resistance, R 2
R M = 8 a 6 ρ 0 ω 4 27 π c 3 M

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