Notes on the radiation impedance, especially of piston-like radiators

摘要: Definitions of the radiation impedance in literature are varied and sometimes ambiguous. This paper starts with a power-based definition then it is shown that other “definitions” based on total force or average pressure radiator restricted to certain conditions. Quantities related impedance, such as effective oscillating mass, end correction, factor efficiency mentioned briefly. Since well known textbook examples impedances spheres cylinders given incorrectly many places literature, vibrating different modes repeated here. Then question discussed why resonators an array really never perform like single prototype resonator quantitatively influence mutual gives broader frequency band absorption array. Further, algorithms approximations for elliptic rectangular baffled pistons derived, which better suited numerical computations than existing ones. Finally, rather general relation presented computation corrections necks shapes, no analytical results available.