Tuned Helmholtz resonator using cavity forcing

Abstract

A Helmholtz resonator includes a chamber at least partially defining a cavity. The chamber has a neck which defines a passage that is in fluid communication with the cavity. The chamber and the neck produce a passive response to a sound wave produced by the internal combustion engine. The sound wave negatively effects engine performance. An active resonator is disposed within the chamber. The active resonator produces a forced response for supplementing the passive response and increasing the band width of the noise attenuating pressure wave. The Helmholtz resonator is in fluid communication with a portion of an air induction system that defines a passageway that carries the sound wave. A driver is connected to the active resonator, which is preferably a loud speaker, to drive the loud speaker and produce the forced response. The driver preferably utilizes a signal source, such as an engine speed signal, to synchronize the forced response with the engine speed. A phase compensator synchronizes the forced response with the sound wave, and an amplifier amplifies the signal to drive the loud speaker.

Dependencies are inferred from the claim text.