Micro-perforated plate (MPP) absorbers are perforated plates with holes typically in the sub mm range and perforation ratios around 1%. The values are typical for applications in air at standard temperature and pressure (STP). The underlying acoustic principle is simple, it is to create a surface with a built in damping which effectively absorbs sound waves. To achieve this, the acoustic impedance of a MPP absorber is normally tuned to be of the order of the characteristic wave impedance in the medium (~ 400 Pa*s/m in air at STP). The traditional application for MPP absorbers has been building acoustics often combined with a so called panel absorber, to create an absorption peak at a selected frequency. However, MPP absorbers made of metal could also be used for noise control close to or at the source in many vehicle applications.
Acoustical Study of Micro- Perforated Plates for Vehicle Applications
Sae Technical Papers
SAE 2009 Noise and Vibration Conference and Exhibition ; 2009
2009-05-19
Conference paper
English
Dissipative Silencers Based on Micro-Perforated Plates
SAE Technical Papers | 2013
|Dissipative Silencers Based on Micro-Perforated Plates
British Library Conference Proceedings | 2013
|Acoustical transparency of perforated panels with fabric linings
British Library Conference Proceedings | 2004
|Development of micro-perforated acoustic elements for vehicle applications
Tema Archive | 2005
|SAE Technical Papers | 2013
|