Valve system for a gas turbine engine

[0001] The present invention relates to a gas turbine engine, and more particularly to a valve system for operation therewith.

[0002] A gas turbine engine, such as a turbofan engine for an aircraft, includes a fan section, a compression section, a combustion section, and a turbine section. An axis of the engine is centrally disposed within the engine, and extends longitudinally through these sections. A primary flow path extends axially through the engine. An annular secondary flow path is generally located radially outward of the primary flow path.

[0003] Cooling air along the secondary flow path is often communicated to the primary flow path during particular operating conditions. In order to assure efficient engine operation and performance, communication of the cooling air from the secondary flow path to the primary flow path needs to be meticulously rationed.

[0004] The valve system according to an exemplary aspect of the present invention is located intermediate a secondary flow path and a primary exhaust flow path. The valve system selectively communicates secondary airflow to control airflow from a higher pressure plenum into a lower pressure flowpath of a gas turbine engine. The valve system generally includes a plate which is slidably mounted relative to a frame for movement between a closed position and an open position.

[0005] Another exemplary aspect of the present invention provides an arcuate plate supported upon arcuate tracks movable between a closed position and an open position.

[0013] FIG. 1 schematically illustrates a gas turbine engine 10 which generally includes a fan section 12, a compressor section 14, a combustor section 16, a turbine section 18, an augmentor section 19, and a nozzle section 20. The compressor section 14, combustor section 16, and turbine section 18 are generally referred to as the core engine. An axis of the engine A is centrally disposed and extends longitudinally through these sections.

[0014] An engine duct structure 22 and an inner cooling liner structure 24 define an annular secondary flow path 26 at least partially around a perimeter of a primary flow path 28 which directs a primary combustion core gas exhaust flow (illustrated schematically by arrow E). It should be understood that the engine duct structure 22 may also at least partially define various airflow paths other than the disclosed secondary flow path 26.

[0015] The secondary flow path 26 guides a secondary airflow C between the engine duct structure 22 and the inner cooling liner structure 24. The secondary airflow as defined herein may be any airflow different from the primary combustion core gas exhaust flow E such as an advent cycle third stream fan flow which may be sourced from the fan section 12 and/or compressor section 14. The secondary airflow C is utilized for a multiple of purposes including, for example, cooling, pressurization, partial shielding and mixing with the core gas flow E in the nozzle section 20 during particular operational profiles. The valve system 30 operates rapidly and repeatedly while configured to be received within minimal package space.

[0016] A valve system 30 is located intermediate the secondary flow path 26 and the primary flow path 28 to selectively communicate secondary airflow C into the primary gas flow path E. For example only, under certain conditions, such as when an aircraft is hovering, less secondary airflow may be required in the nozzle section 20. By blocking the secondary airflow thereto, additional secondary airflow then becomes available for other purposes. It should be understood that the valve system 30 may be utilized in any location and any environment to control airflow injected from a higher pressure plenum into a lower pressure flowpath such as, for example only, in a nozzle section of a gas turbine engine.

[0017] Referring to FIG. 2A, the valve system 30 generally includes a plate 32 which is slidably mounted relative to a frame 34 for movement between a closed position and an open position (FIG. 2B). The plate 32 is movable relative the frame 34 along a slider rail 36 which may be a section of the frame 34.

[0018] The frame 34 may be mounted to a plenum wall such as the inner cooling liner structure 24 (FIG. 1) to provide for communication between the secondary flow path 26 and the primary flow path 28. The frame 34 at least partially surrounds an airflow path 35 (FIG. 2B) which may further guide the airflow between the secondary flow path 26 and the primary flow path 28. The airflow path 35 may include a mesh, grid, metering hole arrangement, honeycomb structure, or such like which directs and smoothes the airflow therethrough as well as reduces noise generation.

[0019] An actuator system 38 having a hydraulic, pneumatic or electromagnetic actuator 40 controls movement of the plate 32 through a linkage 42. The actuator 40 may be located though the engine duct structure 22 such that drive components and such like of the actuator system 38 may be located external to the engine duct structure 22. It should be understood that various actuator systems may be usable with the present invention.

[0020] The linkage 42 generally includes a crank 44 mounted to the frame 34 which engages a roller 46 mounted to the plate 32. Plate roller posts 45 engage slider rail 36 to guide plate 32 thereon. The crank 44, although illustrated in the disclosed embodiment as a generally right-angle bellcrank, may include cranks of various types as well as other linkages may alternatively or additionally be provided.

[0021] Referring to FIG. 3, another embodiment of the valve system 30A includes an arcuate plate 50 supported upon arcuate tracks 52 which are movable relative a frame, guides 54, between a closed position (FIGS. 4A and 4B) and an open position (FIGS. 5A and 5B) through an actuator system 56 (illustrated schematically). The guides 54 are mounted in a fixed location relative to, in one disclosed embodiment, a plenum wall such as the inner cooling liner structure 24 to provide for communication between the secondary flow path 26 and the primary flow path 28. The arcuate plate 50 moves to selectively block the airflow path 35′ between the secondary flow path 26 and the primary flow path 28.

[0022] The arcuate plate 50 may include an angled edge 58 such that a predetermined volume of airflow is communicated relative to movement of the arcuate plate 50. The angled edge 58 may also be arranged to permit a quantity of airflow through the airflow path 35′ even when the arcuate plate 50 is in a closed position. Furthermore, it should be understood that other edge arrangements which provide other airflow passage relative to arcuate plate 50 may alternatively be provided. It should be understood that other opening sequences and arrangements may alternatively or additionally be provided.

[0023] It should be understood that relative positional terms such as “forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like are with reference to the normal operational attitude of the vehicle and should not be considered otherwise limiting.

[0024] It should be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit from the instant invention.

[0025] Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present invention.

[0026] The foregoing description is exemplary rather than defined by the limitations within. Many modifications and variations of the present invention are possible in light of the above teachings. The disclosed embodiments of this invention have been disclosed, however, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.