| 摘要 |
A variable exhaust nozzle (26) for a turbine engine nacelle (16) includes a pair of semi-cowls (58, 60) disposed about a longitudinally extending central axis (14) and a pair of corresponding shells (36, 38) each of which is spaced radially inwardly from the corresponding semi-cowl and is pivotable about a pivot axis (42, 44) between an extended position and a retracted position. The semi-cowls and shells have curved, geometrically similar inner and outer surfaces (86, 100) respectively so that gap (108) between the shells and the cowl is uniform irrespective of the angular orientation of the shells. A seal (128) which includes longitudinally extending legs (128a, 128b) and an optional circumferential leg (128c) prevents detrimental air leakage. Pivotal movement of the shells effects large changes in the discharge area AD of the nozzle without compromising the external aerodynamic characteristics of the nacelle. In one embodiment of the invention, each shell includes an extension (110) which facilitates the attainment of large area changes. The radial uniformity of gap (108) contributes to the durability and simplicity of the seal by ensuring that the seal is not repeatedly compressed and relaxed during operation of the nozzle.
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