초록 ▼

A sound attenuator for an enclosure, in particular, an apparatus for attenuating the sound at the openings which allow air to enter and exit an internal combustion engine enclosure with minimal pressure loss. The attenuator comprises a combination of passive sound absorptive louvers place in series

A sound attenuator for an enclosure, in particular, an apparatus for attenuating the sound at the openings which allow air to enter and exit an internal combustion engine enclosure with minimal pressure loss. The attenuator comprises a combination of passive sound absorptive louvers place in series with a plurality of reactive Helmholtz resonator units mounted in parallel rows in the open area between each pair of louver. The Helmholtz resonators being tuned to attenuate a single or multiple low frequency noise spikes. The attenuator providing improved sound attenuation and requiring substantially less volume than a typically used absduct type silencer.

대표청구항 ▼

An apparatus for attenuating sound from an enclosure, comprising: a frame, said frame being adapted for mounting in a wall, said frame having inner and outer surfaces; a plurality of sound absorptive panels positioned in said frame and being substantially parallel and spaced apart from one another;

An apparatus for attenuating sound from an enclosure, comprising: a frame, said frame being adapted for mounting in a wall, said frame having inner and outer surfaces; a plurality of sound absorptive panels positioned in said frame and being substantially parallel and spaced apart from one another; a plurality of resonator units, each said resonator unit having a preselected volume and an opening of a preselected diameter, a selected number of said resonator units interconnected to form a plurality of first resonator rows; each said first resonator row extending across said frame and being spaced apart from one another and positioned between said sound absorptive panels, said first resonator rows being fixedly positioned to said frame such that each said opening is arranged in a direction substantially parallel to the flow direction of air in and out of said enclosure.