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Duct Attenuation

Attenuation of sound in ducts and pipes is a fundamental area of research within Vipac's Research facility. The development of efficient and cost effective, absorptive duct liners and silencers has lead to a range of innovative products such as the 'BRONO-MUFF', a tuned absorptive / reactive muffler for low frequency noise emissions from boiler houses. Duct liners have been developed for a wide range of applications - from domestic air conditioning ducts to erosion free medically clean ducts for HEPA filters. Silencers and acoustic plenum development has been aided by:

  • extensive twin reverberation chambers for evaluation of acoustic performance;
  • large capacity low noise air supply for testing plenums and silencers under real conditions;
  • an excellent model shop which has allowed scale modells to be built to simulate large silencers or plenums as used in the Taiwan Rail Underground Project;
  • sophisticated analytical tools developed during the Space Shuttle program and now marketed as AutoSEA and Resound through Vipac's US subsidiary Vibro Acoustic Sciences;
  • excellent skills in Fluid Mechanics derived from Wind Tunnel Experiences (Vipac operates a large Boundary Layer Wind Tunnel) and the use of Computational Fluid Dynamics software.



    Vipac's unique combination of analytical and experimental skills coupled with wide industry experience has allowed such breakthroughs as the patented 'Turbulence Trip Silencer' which dramatically reduces low frequency noise emissions from gas turbine exhausts.


    To find out more about these services, please email: