Acoustical absorptive splitter

Abstract

An acoustic absorptive splitter consisting of two absorptive faces separated by a single on-quarter wavelength cavity support is disclosed as an equal substitute for a multi-layered splitter containing a central septum. This construction takes advantage of the reflective properties of the absorptive face sheets to support standing waves in the tuning cavities and in the duct cross modes. The utilization of these design principles permits significant silencer size and weight reduction. It also permits reduced splitter manufacturing costs by elimination of two layers of materials, difficult internal bonding and improvements in quality.

What is claimed is:  
     
         1 . An acoustic splitter for use in attenuating sound through the absorption of sound energy having a fixed wavelength, said splitter comprising a plurality of one-quarter wavelength cavities defined by a cavity support structure, said cavities being bounded on either end by an absorptive face sheet.  
     
     
         2 . The acoustic splitter of  claim 1 , wherein said absorptive face sheets are composed of perforated metal.  
     
     
         3 . The acoustic splitter of  claim 1 , wherein said absorptive face sheets are composed of fibermetal.  
     
     
         4 . The acoustic splitter of  claim 1 , wherein said absorptive face sheets are composed of metal screening.  
     
     
         5 . The acoustic absorptive splitter of  claim 1 , wherein said absorptive face sheets are composed of a combination of absorptive materials.  
     
     
         6 . The acoustic splitter of  claim 1 , wherein said absorptive face sheets are composed of a porous non-metallic material.  
     
     
         7 . The acoustic splitter of  claim 1 , wherein said cavity support is arranged in a honeycomb configuration.  
     
     
         8 . The acoustic splitter of  claim 1 , wherein said cavity support is arranged in an egg crate-type configuration.  
     
     
         9 . An acoustical silencer for use in attenuating sound through the absorption of sound energy having a fixed wavelength, said acoustical silencer comprising at least two acoustic splitters comprising a plurality of one-quarter wavelength cavities defined by a cavity support structure, said cavities being bounded on either end by an absorptive face sheet, wherein said splitters are spaced at quarter wavelengths.  
     
     
         10 . An acoustical silencer for use in attenuating sound through the absorption of sound energy having a fixed wavelength, said acoustical silencer comprising first and second acoustic splitters comprising a plurality of one-quarter wavelength cavities defined by a cavity support structure, said cavities being bounded on either end by an absorptive face sheet, wherein said splitters are spaced at quarter wavelengths, said second acoustic splitter having a thickness one half the thickness of said first acoustic splitter.