Patent Application
20090241550
1. Technical Field
The disclosure generally relates to gas turbine engines.
2. Description of the Related Art
Varying the nozzle exhaust area of a gas turbine engine can affect engine performance. By way of example, varying the nozzle exhaust area can alter propulsive efficiency, fan stability, noise output, and/or fuel consumption.
Gas turbine engine systems involving variable nozzles with flexible panels are provided. In this regard, an exemplary embodiment of a flexible panel assembly for a gas turbine engine comprises: a flexible panel operative to define at least one of a throat area and an exit area of a nozzle of a gas turbine engine, the panel being further operative to selectively exhibit a range of positions to regulate exhaust of the engine.
An exemplary embodiment of a nozzle assembly for a gas turbine engine comprises: a nozzle having a throat area and an exit area; and a flexible panel operative to variably alter at least one of the throat area and the exit area to regulate exhaust flow of the nozzle.
An exemplary embodiment of a gas turbine engine comprises: a compressor; a turbine operative to drive the compressor; and a nozzle assembly positioned downstream of the turbine, the nozzle assembly defining a throat area and an exit area and having a flexible panel operative to selectively move between an open position and a closed position such that gas flowing through the nozzle is regulated.
Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Gas turbine engine systems involving variable nozzles with flexible panels are provided, several exemplary embodiments of which will be described in detail. In some embodiments, such a flexible panel is deflected in a gas turbine engine to create a desired shape in order to vary the nozzle exhaust area of the engine dynamically. Varying the nozzle exhaust area in a gas turbine engine can alter engine performance characteristics such as increasing fuel efficiency.
As shown in
In this regard, reference is made to the perspective diagram of
The flexible panel 34 is configured to be variably deflected along a range of positions between a full open position, at which the nozzle assembly 10 exhibits a maximum exit area, and a full closed position, at which the nozzle assembly 10 exhibits a minimum exit area. As the flexible panel 34 is variably positioned, gas stream 26 (entering from a duct 16 of the nozzle assembly 10) is regulated.
The nozzle assembly 10 also incorporates a support structure 32 located within a lower cavity 36. The support structure 32 is configured to provide alignment and structural support to the flexible panel 34 from the underside (i.e., the non-gas path side) as the flexible panel 34 is variably positioned. In some embodiments (such as in
The flexible panel 34 incorporates stiffening stays 30 to maintain the throat profile of the nozzle assembly 10. The stiffening stays 30 are structural stiffeners tailored to provide a desired aerodynamic shaping of the flexible panel 34 at key performance locations over the entire range of motion of the flexible panel 34. In this embodiment, the stiffening stays 30 are formed of elongated strips of semi-rigid material extending across the width of the panel, although various other shapes, orientations and/or materials can be used in other embodiments.
In some embodiments, the flexible panel 34 may be all or partially comprised of a flexible elastomeric material, such as a fluorosilicone elastomer composite. Such a panel can be particularly well adept at sealing undesirable cracks and gaps. Metallics, organic composites, and ceramic composite materials are also envisioned to be suitable panel materials depending on placement within the panel structure and engine application. In higher temperature applications, for example, edge sealing could be performed with flexible metallic elements to cover cracks and gaps. Additionally, the relatively low translation and deflection requirements of the flexible panel 34 to vary the nozzle throat area 12 and/or nozzle exit area 14 can result in reduced actuation load requirements for positioning the panel.
In some embodiments, a nozzle assembly can incorporate a pressurized plenum. The pressurize plenum can be located in a lower cavity 36, for example, on a side of the panel opposite the gas path. Such a pressurized plenum is configured to provide pressure balancing of the panel to reduce actuation loads.
Notably, the embodiment of
The actuation mechanism between the actuator 42 and flexible panel 34 can be optimized for expected operating conditions and can incorporate one or more of a variety of linkages, levers, gears, and/or cam designs, chosen to facilitate reduced actuator loading yet increase operating speed.
It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. By way of example, in some embodiments, a flexible panel 34 can be configured to alter a nozzle throat asymmetrically in order to affect yaw vectoring of the flow. In some embodiments, this can be accomplished by the use of differential actuation of multiple actuators. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims.
