Development of Adaptive Acoustic Impedance Control Technologies of Acoustic Duct Liner

Table 2

Three models of AAC technology I, II, and III.

	AAC technology; I model	AAC technology; II model	AAC technology; III model
(1) Usage of apparatus	Mobile reflective plate apparatus	Tunable perforated plate apparatus	Both mobile reflective plate and tunable plate apparatuses
(2) Mainly controllable acoustic impedance part of liner	Reactance part of acoustic impedance of liner	Resistance part of acoustic impedance of liner	Both reactance and resistance parts of acoustic impedance of liner