| 摘要 |
A sandwich type acoustical absorbing panel for use adjacent high speed gas flow areas in and around the engines of high speed aircraft. The panel comprises a pan type base having an imperforate base member and upstanding sides and end walls, an acoustic absorbing medium is disposed within the pan type base, a rigid perforated plate is secured to the distal surfaces of the upstanding sides and end walls for enclosing the acoustic absorbing medium and a sheet of fine woven mesh is secured to the outer surface of the rigid perforated plate. The outer positioned fine woven mesh enhances acoustic properties of the panel and substantially prevents entry of water, dust, chemicals and similar foreign matter from penetrating into the panel structure and reduces the aerodynamic drag loss normally encountered by high speed gas flows across perforated material, such as, that normally used for the outer surface of acoustic panels.
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