Patent ID: 6290022
Filing Date: 2001-09-18
Classification: G10K

Abstract:
Surface like-sheet absorber for sound waves in fluids with frequencies in the acoustic range, comprising a sound-side perforated plate having a length and width and holes (8) extending through the thickness of said plate and a closed cavity situated behind and connected to said perforated plate, said absorber cavity having a random and irregular checkerwork (2) throughout said length and width including a plurality of spaced and aligned webs with their narrow sides perpendicular to a principal surface of said perforated plate (3) and their long side edges (5) connected in a soundpressure-resistant and fluidtight manner to a rear side (6) of said perforated plate (3), said cavity having a two-dimensionally extended cavity boundary (4) aligned with the same orientation as said perforated plate and spaced therefrom to form a plurality of chamber resonators (7) of different volumes.