Reciprocity and the active control of distributed acoustic sources (L)

The velocity distributions of a pair of arbitrary acoustic sources are approximated by arrays of elementary sources, and a reciprocal relationship is established between the generalized force on one source and the total velocity of the other source. When the two distributed sources are individually constrained to vibrate with a single phase and are used for active sound control, it is shown that the attenuation in sound power from the pair of sources is the same regardless of whether one source velocity is fixed and the velocity of the other source is adjusted to minimize the power output, or vice versa