| 摘要 |
A gas turbine engine comprises a fan section (12), a compressor (14), a combustor (16) and a turbine (18) and includes a nacelle (22) having an inner nacelle surface (32) defining an inlet duct (42). The inner surface (32) is designed to reduce an inlet duct area (64) of the inlet duct to increase acoustic attenuation. The gas turbine engine also includes a spinner (48), disposed forward of the fan section (12), that includes features to increase acoustic attenuation. In one embodiment of the present invention, the nacelle (22) includes a nacelle contoured surface (100) protruding radially inward from the inner nacelle surface (32) to reduce the inlet duct area (64). In a further embodiment of the present invention, the spinner includes a spinner contoured surface (104) for reducing the inlet duct area. In other embodiments, the nacelle (22) and/or the spinner (48) include an inflatable bladder (70), a SMA actuator (84), a fluidic actuator (90), or a combination thereof, selectively activated to increase acoustic attenuation during certain conditions of an aircraft. |
