| 摘要 |
#CMT# #/CMT# The device has a compressor e.g. centrifugal compressor, and an annular passage (12) for supplying air to the compressor. A radial air inlet (34) including lips (30, 32) is connected to the passage in which the lips are partially formed by acoustic attenuators (40, 42) e.g. Helmholtz attenuators. The attenuators attenuate sound frequencies produced by rotation of the compressor, where the lips are made of fibrous reinforcement composite material densified by resin. Another set of acoustic attenuators is integrated to a metallic case (14) defining the passage of the compressor. #CMT#USE : #/CMT# Device for damping sound of a gas turbine engine (claimed) of a helicopter. #CMT#ADVANTAGE : #/CMT# The provision of the acoustic attenuators eliminates encumbrance problem and avoids re-examining of the design of a gas turbine engine. The configuration of the device enables efficient attenuation of noise generated by the compressor in a simple manner, thus allowing easy adaptability of the device to the existing engines. The lips are made of fibrous reinforcement composite material densified by resin, thus avoiding increase in mass of the attenuators and protecting covering of the air inlet by an anti-frosting grill. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a partial enlarged semi-sectional view of the integration of acoustic attenuators to lips of a radial air inlet for a compressor of a gas turbine engine. 12 : Annular passage 14 : Metallic case 30, 32 : Lips 34 : Radial air inlet 40, 42 : Acoustic attenuators. |
