Turbine engine secondary ejector system

According to an aspect, an ejector member includes an annular member; a vent arranged at the annular member, the vent having an inlet at a first surface of the annular member, the vent further having an outlet arranged radially inward from a second surface of the annular member; and a vane extending radially inward from the second surface of the annular member.

BACKGROUND

Exemplary embodiments relate to turbine engine exhaust systems, and more particularly, to a turbine engine secondary flow ejector system.

Turbine engine systems receive air from outside of an aircraft. A primary portion of the cooling air is channeled toward a core of an engine, where the fuel is injected and ignited. A secondary portion of the air is channeled to bypass the core. The bypassing air and the core air are both expelled toward an exhaust duct. The bypassing air interacts with the core air in the exhaust duct, which reduces the temperature in the exhaust duct and reduces engine noise. However, the interaction also results in a disruption of an overall flow of the air in the exhaust duct.

Conventional turbine engine systems add a secondary flow ejector gap around the core exhaust, which pulls the engine bay flow toward the exhaust duct. Conventional turbine engine systems also add a deswirl system to maximize the secondary flow of air being released into the exhaust duct. However, even with a deswirl system, expelled hot air may be pulled back from the exhaust duct and flow toward the engine bay.

BRIEF DESCRIPTION

According to one embodiment, an ejector member includes an annular member; a vent arranged at the annular member, the vent having an inlet at a first surface of the annular member, the vent further having an outlet arranged radially inward from a second surface of the annular member; and a vane extending radially inward from the second surface of the annular member.

In addition to one or more of the features described above or below, or as an alternative, the ejector member further comprises a plurality of vents.

In addition to one or more of the features described above or below, or as an alternative, the ejector member further comprises a plurality of vanes.

In addition to one or more of the features described above or below, or as an alternative, each vent of the plurality of vents has a respective curved surface profile.

In addition to one or more of the features described above or below, or as an alternative, each vent of the plurality of vents has an angled surface profile.

In addition to one or more of the features described above or below, or as an alternative, at least one vane of the plurality of vanes is arranged between a first vent and a second vent.

In addition to one or more of the features described above or below, or as an alternative, the annular member comprises an exhaust duct.

According to another embodiment, an ejector assembly includes an engine exhaust frame having a first casing and a second casing spaced apart and radially outward from the first casing; an annular member attached to the second casing; a plurality of vents arranged at the annular member, each vent having an inlet at a first surface of the annular member, each vent further having an outlet arranged radially inward from a second surface of the annular member; and a plurality of vanes extending radially inward from the second surface of the annular member.

In addition to one or more of the features described above or below, or as an alternative, the second casing has a tube-shaped body that extends along and is coaxial with a longitudinal axis of the engine exhaust frame.

In addition to one or more of the features described above or below, or as an alternative, the first casing has a tube-shaped body that extends along and is coaxial with the longitudinal axis of the engine exhaust frame.

In addition to one or more of the features described above or below, or as an alternative, the annular member comprises an exhaust duct.

In addition to one or more of the features described above or below, or as an alternative, each vane of the plurality of vanes is attached to the first casing.

In addition to one or more of the features described above or below, or as an alternative, the ejector assembly further includes a hub connected to the first casing.

According to yet another embodiment a rotary-wing aircraft includes a rotor; a turbine engine for driving the rotor; an exhaust system for receiving an exhaust from the turbine engine; the exhaust system comprising: an engine exhaust frame; and an engine exhaust frame having a first casing and a second casing spaced apart and radially outward from the first casing; an annular member attached to the second casing; a plurality of vents arranged at the annular member, each vent having an inlet at a first surface of the annular member, each vent further having an outlet arranged radially inward from a second surface of the annular member; a plurality of vanes extending radially inward from the second surface of the annular member.

In addition to one or more of the features described above or below, or as an alternative, the second casing has a tube-shaped body that extends along and is coaxial with a longitudinal axis of the engine exhaust frame.

In addition to one or more of the features described above or below, or as an alternative, the first casing has a tube-shaped body that extends along and is coaxial with the longitudinal axis of the engine exhaust frame.

In addition to one or more of the features described above or below, or as an alternative, each vent of the plurality of vents is arranged equidistant from an adjacent vent.

In addition to one or more of the features described above or below, or as an alternative, the annular member comprises an exhaust duct.

In addition to one or more of the features described above or below, or as an alternative, the exhaust system further includes a barrier mechanism operable to block the outlet hole.

In addition to one or more of the features described above or below, or as an alternative, the rotary-wing aircraft, further includes a translational thrust system; and a propeller rotor operable to be driven by the turbine engine.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatuses are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring toFIGS.1and2, an exhaust assembly100, according to some embodiments, is shown. The exhaust assembly100includes an exhaust frame102. The exhaust frame102includes an outer casing104, and inner casing106, and a number of struts108. The outer casing104may have a tube-shaped body that extends along and is coaxial with a longitudinal axis110of the exhaust frame102. The inner casing106may also have a tube-shaped body that extends along and is coaxial with the longitudinal axis110of the exhaust frame102. As illustrated inFIG.1, the outer casing104is arranged to be spaced apart from and positioned radially outward from the inner casing106. The struts108connect to the outer casing104to the inner casing106. The exhaust assembly100further includes an annular member112that includes a plurality of vents114. The annular member112is generally tubular and is configured to have a radius that allows it to be attached at an inner surface to be flush with an outer surface of an end of the outer casing104. In addition to the vents114, the annular member112includes a plurality of vanes116that extend radially inwardly from an inner surface118of the annular member112and are, in some embodiments, configured to be connected to either the inner casing106or a hub120that is connected to the inner casing106. In other embodiments, the annular member112includes a plurality of vanes116that extend radially inward but only partially span the gap between the inner casing106or a hub120that is connected to the inner casing106. In yet other embodiments, the annular member112does not include any vanes118, as shown inFIG.2.

Each vent114includes an inlet406and an outlet408, as shown onFIG.4B. The inlet406being arranged at the outer surface122. The outlet408being arranged radially inwardly from the inner surface118of the annular member112. Each vent114protrudes radially inwardly from the inner surface118of the annular member112and in the path of a primary exhaust flow124. The primary exhaust flow124is a flow of air that has been received from outside an aircraft10and passes through an engine22. The temperature and speed of the flow of air increases as it passes through an engine22due to the engine combustion of fuel and air. The heated flow of air passes across the struts108and is expelled into the exhaust duct128.

An exhaust ejector126includes a generally annulus shaped open area defined by the outer surface122of the annular member112and an inner surface of the exhaust duct128. The exhaust ejector126is configured to direct a portion of the secondary exhaust flow132A132B through the exhaust ejector126and into the exhaust duct128. The secondary exhaust flow132is a flow of air received from outside of the aircraft10, but bypasses the engine22and is expelled directly into the exhaust duct128. Although the secondary exhaust flow132A132B has a higher temperature than the air from the outside due to passing over the hot engine sections, it is cooler than the primary exhaust flow124. An aircraft's exhaust system is configured such that the cooler air in the exhaust duct128has lower air pressure than the hotter air about the engine area. This results in the air in the higher pressure area around the engine moving toward the lower pressure area in the exhaust duct128.

During operation, the primary exhaust flow124and the secondary exhaust flow132A132B flow into the exhaust duct128. Each vent114is arranged within the path of the primary exhaust flow124and causes the primary exhaust flow124to diverge from its path to flow past the vents114prior to reaching the exhaust duct128. A first portion of the secondary exhaust flow132A flows through the exhaust ejector126and into the exhaust duct128. A second portion of the secondary exhaust flow132B is received by the inlet406of the vent114and is expelled from the outlet408into the exhaust duct128. The second portion132B is expelled into the exhaust primary flow124at a non-linear angle to the direction of the first portion. The angle of the direction of the second portion132B is based at least in part on an angle of the vent114in relation to the inner surface118of the annular member112. Therefore, the vent114both manipulates the primary exhaust flow124and entrains the secondary exhaust flow132B. This manipulation results in a higher air pressure gradient between the air in an engine area (not shown) and the air in the exhaust duct128. The higher pressure gradient results in air being received from the outside and being expelled into the exhaust primary flow124at a faster rate than with a conventional exhaust system. This reduces the probability that hot air expelled into the exhaust duct is pulled back into the engine area. The primary exhaust124, and secondary exhausts132A132B further mix in the exhaust duct128before the combined flows are expelled into the environment outside the aircraft10.

Referring toFIG.3, a cross-sectional diagram of another embodiment of an exhaust assembly300is shown. The exhaust frame302is attached to an annular member304. The annular member304includes a plurality of vents306arranged along a central portion of the annular member304. The annular member304further extends out to form an exhaust duct308. In other words, the annular member304and the exhaust duct308are integrally formed and not distinct elements of an exhaust system. A radius of the annular member304increases from a proximal end310to a housing312such that a space between the annular member304and the housing is sealed such that there is no open annulus surrounding the annular member304. Therefore, the entire secondary exhaust flow314flows through the vents306.

A vent profile may vary, as illustrated inFIGS.4A and4B. As illustrated inFIG.4A, a curved vent400is defined by a convex surface402protruding away from an outer casing404. The curved vent400includes an inlet406for receiving a flow of air and an outlet408for expelling the flow of air. Referring toFIG.4B, a cross-section of the curved vent400is shown. As illustrated, a bottom surface410of the vent400forms a non-linear angle with a top surface412of the outer casing404. During operation, a first portion of the secondary exhaust flow414A flows in a first direction over the outer casing404. Additionally, a second portion of the secondary exhaust flow414B is channeled through the curved vent400at a non-linear angle to the direction of the first portion of the secondary exhaust flow414A. Furthermore, the arrangement of the curved vent400in a path of the primary exhaust flow416, causes the primary exhaust flow to be redirected to flow around the curved vent400.

Referring toFIG.5, an embodiment of an angled vent500is defined by three planar facets502504506. The first facet502is arranged at a non-linear angle to a second facet504. The second facet504is arranged at a non-linear angle to a third facet504. Each angle may be determined based on a desired outlet shape and a desired flow of air. It should be appreciated that althoughFIG.5illustrates three planar facets502504506, the angled vent500may include two or more planar facets. The angled vent500may also further include a combination of at least one planar facet and at least one angled surface. It should be appreciated that such planar facets could be replaced by various curved facets. The number of facets, facet contour, and adjoining methodology of the facets are considered different embodiments of the vent designs illustrated inFIGS.4A,4B, and5.

Referring toFIG.6, a guided vent600is shown. The guided vent600includes an outlet frame602that itself includes one or more outlet holes604. The outlet frame602is a barrier that causes a flow of air to be expelled through the outlet hole(s)604. The outlet hole(s)604may have various sizes and shapes of varying complexity based on a desired flow of air. In some embodiments, a movable barrier mechanism606may be incorporated to block air from passing through one or more of the outlet hole(s)604. The movable barrier mechanism606may be a flap or a slidable screen. The movable barrier mechanism606may include an actuator (not shown) operated by a crew member of the aircraft10. It should be appreciated that although an angled vent and a curved vent have been illustrated, a vent may include any geometric profile and further include various widths and lengths based at least in part on a desired flow of the primary exhaust flow and secondary exhaust flow.

With reference now toFIG.7, an example of a vertical takeoff and landing (VTOL) aircraft is schematically illustrated. The aircraft10in the disclosed, non-limiting embodiment includes a main rotor assembly12supported by an airframe14having an extending tail16, which mounts an anti-torque system/tail rotor (TR) system18. The main rotor assembly12is driven about an axis of rotation A through a main rotor gearbox (MGB)20by one or more engines22. The engines22generate the power available for flight operations and couple such power to the main rotor assembly12and the TR system18through the MGB20. The main rotor assembly12includes a multiple of rotor blades24mounted to a rotor hub26. Although a particular helicopter configuration is illustrated and described in the disclosed embodiment, other configurations and/or machines, such as high speed compound rotary-wing aircraft with supplemental translational thrust systems, dual contra-rotating, coaxial rotor system aircraft, turbo-props, tilt-rotors tilt-wing aircraft and non-aircraft applications such as wind turbines, or any application with a turbine engine (including axial and centrifugal) that expels a hot exhaust will also benefit here from.