A nozzle assembly for gas turbine power plants, particularly aircraft jet engines, which incorporates a generally annular splitter dividing the nozzle into two parts and provided on its surface with suitable sound-absorbing material. Incorporated into the splitter and forming a part thereof is apparatus for varying the cross-sectional area of the nozzle exit and, hence, the operating characteristics of the power plant. This latter means preferably comprises a plurality of arcuate segments hinged to the splitter and actuable from a position where they are flush with the remainder of the splitter surface to extended positions where they effectively reduce the nozzle cross-sectional area. The assembly, therefore, performs two functions. First, it provides additional sound-absorbing area; and, secondly, it acts as a nozzle area control device.
A thrust reverser for a fan jet engine having a splitter in the fan duct in a plane with the fixed cascades is designed with blocker doors positioned to block flow between the splitter and the outer wall when in the deployed position. The splitter and supports are positioned to simultaneously uncover the cascades and block flow in the remaining portion of the duct. This design contemplates elimination of the blocker door drag links that typically extends into the duct passageway.
A noise suppressor for installation on the discharge or aft end of a turbo fan engine. Within the suppressor are fixed annular airfoils which are positioned to reduce the relative velocity between the high temperature fast moving jet exhaust and the low temperature slow moving air surrounding the same. Within the suppressor nacelle is an exhaust jet nozzle which constrains the shape of the jet exhaust to a substantially uniform elongate shape irrespective of the power setting of the engine. Fixed ring airfoils within the suppressor nacelle therefore have the same salutary effects irrespective of the power setting at which the engine is operated.
3938742 - Cascade plug nozzle - Owned by The United States of America as represented by the United States Counsel-Code GP (Washington, DC)
An exhaust nozzle for a jet aircraft provides jet noise suppression. The nozzle includes a plurality of coaxial airfoil ring segments which are spaced serially along the longitudinal axis of the nozzle to define a plurality of annular coaxial channels therebetween. The diameters of the segments progressively decrease downstream along this axis and the exits of the channels are non-coplanar. The radial depths of the channels are small as compared with the axial distance between adjacent channel exits so that noise is emitted non-simultaneously from the channel exits as a series of weakened pulses staggered in time. The boattail angles of the outer surfaces of the ring airfoil segments increase in magnitude with increasing distance downstream to reduce drag.
A two dimensional expansion nozzle having a rotating plug serves to block flow, meter flow and afford thrust vectoring. Adjustable walls cooperate to obtain these features and may be adjusted independently to vary nozzle throat area. Cooling means are disclosed. This invention has particular application for VTOL aircraft.
A sound attenuation honeycomb sandwich wherein each cell of a first layer acts as the neck of the resonator and each cell of the second layer acts as the cavity. The purpose of the first layer is to reduce the natural frequency of the resonator by increasing the length of the neck without using a solid, thick, sheet. The skins connected to the faying edges of the first layer are perforated to provide the necessary openings for the neck to function as the stiffness element in the resonator.
