Minimization of acoustic power and condition of zero power phenomenon in plane structure of infinite baffle

Abstract

In active noise control，if total acoustic power is minimized，absorption and blowout of acoustic energy around the control source are balanced，and a zero power phenomenon occurs in which the time average of control power becomes zero. In this study, we aim at generalization of this phenomenon, the sound source is regarded as a flat plate structure embedded in an infinite baffle, and the generation condition of the zero power phenomenon is considered. First, we will clarify the reciprocity when the zero power phenomenon occurs in the case of three point sources. Next, the reciprocity of the zero power condition is clarified based on the control law derived from the sound sources emitted from the three flat plate structures.