(Minimization of sound power and condition of zero power phenomena)

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 research，we aim at generalization of the said phenomenon，and consider the generation condition of the zero power phenomenon in the case of multiple control sound sources. Next，based on the derived control rules，we will clarify the change in acoustic power due to the increase in the number of sound sources and the position from the viewpoint of numerical analysis. Finally，the zero power control law in the case of expanding the control sound source to n control sources is derived.Numerical analysis using the derived control law to prove importance.