Patent Description:
An aircraft propulsion system may include an inlet structure and a gas turbine engine. The inlet structure directs air into the gas turbine engine. Some known inlet structures include a variable airflow inlet area for tailoring a mass flow of the air entering the gas turbine engine. While these known inlet structures have various advantages, there is still room in the art for improvement. There is a need in the art therefore for an improved inlet assembly with a variable airflow inlet area.

<CIT> discloses improvements to channel-wing aircraft, especially those with vertical take-off.

<CIT> discloses gas inlet conversion and protection means.

According to an aspect of the present invention, an assembly is provided for an aircraft propulsion system in accordance with claim <NUM>.

The following optional features may be applied to the above aspect.

An aft end of the inlet lip structure may be axially spaced from a forward end of the fixed structure when the moveable structure is at the forward position to open the outer airflow inlet passage. The aft end of the inlet lip structure may be axially abutted with the forward end of the fixed structure when the moveable structure is at the aft position to close the outer airflow inlet passage.

A forward end of the deflector may be axially displaced from a forward end of the fixed structure when the moveable structure is at the aft position. The forward end of the deflector may be axially at, and radially spaced from, the forward end of the fixed structure when the moveable structure is at the forward position to provide the virtual ramp into the inner airflow inlet passage.

The inlet lip structure may be configured as or otherwise include a tubular inlet lip structure. The deflector may be configured as or otherwise include a tubular deflector.

A pylon may extend axially between and/or may be connected to the inlet lip structure and the deflector.

The deflector may be configured to move axially with the inlet lip structure as the moveable structure moves between the aft position and the forward position.

The deflector may be configured to form a virtual ramp into the airflow inlet passage when the moveable structure is in the forward position.

A leading edge of the deflector may be abutted radially against the fixed structure when the moveable structure is in the aft position. The leading edge of the deflector may be radially displaced from the fixed structure when the moveable structure is in the forward position.

A radius of the leading edge of the deflector to the centerline may remain uniform as the deflector moves with the moveable structure axially along the centerline between the aft position and the forward position.

The variable area inlet may be configured without the blind cavity when the moveable structure is in the aft position.

The deflector may extend circumferentially about a portion of the fixed structure at the forward end of the fixed structure when the moveable structure is in the forward position.

When the moveable structure is in the aft position, the aft end of the inlet lip structure may be abutted axially against the forward end of the fixed structure.

The airflow inlet passage may extend radially through the variable area inlet when the moveable structure is in the forward position.

The assembly may also include an inlet duct. The airflow inlet passage may be configured as or otherwise include an outer airflow inlet passage. The variable area inlet may also include an inner airflow inlet passage at a forward end of the moveable structure. The inlet duct may be fluidly coupled with the inner airflow inlet passage when the moveable structure is in the aft position. The inlet duct may be fluidly coupled with the inner airflow inlet passage and the outer airflow inlet passage when the moveable structure is in the forward position.

The inlet duct may be configured to direct air received from the inner airflow inlet passage and the outer airflow inlet passage into a core flowpath and/or a bypass flowpath of the aircraft propulsion system when the moveable structure is in the forward position.

The variable area inlet may be configured to regulate airflow through the inner airflow inlet passage by moving the moveable structure between the aft position and the forward position.

The airflow inlet passage may include a plurality of ports through the variable area inlet. The ports may be arranged circumferentially about the centerline in an array.

The present disclosure may include any one or more of the individual features disclosed above and/or below alone or in any combination thereof, insofar as they fall within the scope of the appended claims.

<FIG> illustrates an aircraft propulsion system <NUM> for an aircraft such as, but not limited to, a commercial airliner or cargo plane. The aircraft propulsion system <NUM> includes a gas turbine engine <NUM> and a nacelle <NUM>.

The gas turbine engine <NUM> may be configured as a high-bypass turbofan engine. The gas turbine engine <NUM> of <FIG>, for example, includes a fan section <NUM>, a compressor section <NUM>, a combustor section <NUM> and a turbine section <NUM>. The compressor section <NUM> may include a low pressure compressor (LPC) section 27A and a high pressure compressor (HPC) section 27B. The turbine section <NUM> may include a high pressure turbine (HPT) section 29A and a low pressure turbine (LPT) section 29B.

The engine sections <NUM>-29B are arranged sequentially along an axial centerline <NUM> (e.g., a rotational axis) of the gas turbine engine <NUM> within an aircraft propulsion system housing <NUM>. This housing <NUM> includes an outer housing structure <NUM> and an inner housing structure <NUM>.

The outer housing structure <NUM> includes an outer case <NUM> (e.g., a fan case) and an outer structure <NUM> of the nacelle <NUM>; e.g., an outer nacelle structure. The outer case <NUM> houses at least the fan section <NUM>. The outer nacelle structure <NUM> houses and provides an aerodynamic cover for the outer case <NUM>. The outer nacelle structure <NUM> also covers a portion of an inner structure <NUM> of the nacelle <NUM>; e.g., an inner nacelle structure, which may also be referred to as an inner fixed structure (IFS). More particularly, the outer nacelle structure <NUM> axially overlaps and extends circumferentially about (e.g., completely around) the inner nacelle structure <NUM>. The outer nacelle structure <NUM> and the inner nacelle structure <NUM> thereby at least partially or completely form an annular bypass flowpath <NUM> within the aircraft propulsion system <NUM>.

The inner housing structure <NUM> includes an inner case <NUM> (e.g., a core case) and the inner nacelle structure <NUM>. The inner case <NUM> houses one or more of the engine sections 27A-29B, which engine sections 27A-29B may be collectively referred to as an engine core. The inner nacelle structure <NUM> houses and provides an aerodynamic cover for the inner case <NUM>.

Each of the engine sections <NUM>, 27A, 27B, 29A and 29B includes a bladed rotor <NUM>-<NUM>. The fan rotor <NUM> and the LPC rotor <NUM> are connected to and driven by the LPT rotor <NUM> through a low speed shaft <NUM>. The HPC rotor <NUM> is connected to and driven by the HPT rotor <NUM> through a high speed shaft <NUM>. The shafts <NUM> and <NUM> are rotatably supported by a plurality of bearings (not shown). Each of these bearings is connected to the aircraft propulsion system housing <NUM> (e.g., the inner case <NUM>) by at least one stationary structure such as, for example, an annular support strut.

During operation, air enters the aircraft propulsion system <NUM> through an aircraft propulsion system inlet structure <NUM>. This air is directed through an inlet duct <NUM> and into an annular core flowpath <NUM> and the bypass flowpath <NUM>. The core flowpath <NUM> extends axially along the axial centerline <NUM> within the aircraft propulsion system <NUM>, through the engine sections 27A-29B, to a core nozzle outlet, where the core flowpath <NUM> is radially within the inner case <NUM>. The bypass flowpath <NUM> extends axially along the axial centerline <NUM> within the aircraft propulsion system <NUM> to a bypass nozzle outlet, where the bypass flowpath <NUM> is radially between the outer nacelle structure <NUM> and the inner nacelle structure <NUM>. The air within the core flowpath <NUM> may be referred to as "core air". The air within the bypass flowpath <NUM> may be referred to as "bypass air".

The core air is compressed by the compressor rotors <NUM> and <NUM> and directed into a combustion chamber of a combustor in the combustor section <NUM>. Fuel is injected into the combustion chamber and mixed with the compressed core air to provide a fuel-air mixture. This fuel-air mixture is ignited and combustion products thereof flow through and sequentially cause the turbine rotors <NUM> and <NUM> to rotate. The rotation of the turbine rotors <NUM> and <NUM> respectively drive rotation of the compressor rotors <NUM> and <NUM> and, thus, compression of the air received from a core airflow inlet <NUM>. The rotation of the LPT rotor <NUM> also drives rotation of the fan rotor <NUM>, which propels bypass air through and out of the bypass flowpath <NUM>. The propulsion of the bypass air may account for a majority of thrust generated by the turbine engine <NUM>. The aircraft propulsion system <NUM> of the present disclosure, however, is not limited to the exemplary gas turbine engine configuration described above.

Optimal mass flow requirements of the air entering the aircraft propulsion system <NUM> through the aircraft propulsion system inlet structure <NUM> may change depending upon one or more parameters. These parameters may include, but are not limited to, modes of operation, aircraft maneuvers and operating conditions. For example, where the aircraft flies at supersonic speeds, a first mass flow of the air may be directed through the aircraft propulsion system inlet structure <NUM> into the aircraft propulsion system <NUM>. When the aircraft flies at subsonic speeds, a second mass flow of the air may be directed through the aircraft propulsion system inlet structure <NUM> into the aircraft propulsion system <NUM>, where the second mass flow is greater than the first mass flow.

To accommodate the changing mass flow requirements for the aircraft propulsion system <NUM>, the aircraft propulsion system inlet structure <NUM> is configured as a variable area inlet <NUM>. Referring to <FIG> and <FIG>, this variable area inlet <NUM> includes a center body <NUM>, an aft fixed structure <NUM> and a forward moveable (e.g., a translating) structure <NUM>. These inlet components <NUM>, <NUM> and <NUM> are configured to provide the variable area inlet <NUM> with an annular inner airflow inlet passage <NUM> and a (e.g., substantially annular) outer airflow inlet passage <NUM> (see <FIG>). Briefly, the inner airflow inlet passage <NUM> of <FIG> and <FIG> is configured as a primary airflow inlet passage, which inlet passage may be a variable area inlet passage or a fixed area airflow inlet passage as described below. The outer airflow inlet passage <NUM> of <FIG> is configured as a secondary airflow inlet passage, which inlet passage is a variable area airflow inlet passage.

Referring to <FIG>, the center body <NUM> forms an inlet cone and/or an inlet spike of the aircraft propulsion system <NUM>. The center body <NUM> extends axially along an axial centerline <NUM> (e.g., an axis) of the variable area inlet <NUM> (see <FIG> and <FIG>) from an aft, downstream end <NUM> of the center body <NUM> to a forward, upstream end <NUM> (e.g., a tip, a point) of the center body <NUM>, which centerline <NUM> may be coaxial with the axial centerline <NUM>. The center body <NUM> extends circumferentially about (e.g., completely around) the axial centerline <NUM>, <NUM>. The center body <NUM> extends radially outward to an outer side <NUM> of the center body <NUM>.

The center body outer side <NUM> of <FIG> is configured with a partially tapered geometry. The center body <NUM> of <FIG>, for example, includes a plurality of outer (e.g., exterior) surfaces 86A and 86B located at the center body outer side <NUM>. The forward, upstream tapered surface 86A is located at the center body forward end <NUM>. Note, the term "forward, upstream tapered surface", or "forward tapered surface" for short, may describe a surface that tapers in a forward, upstream direction. The plateau surface 86B is located at the center body aft end <NUM>.

The forward tapered surface 86A may have a conical geometry, or another tapered geometry such as a semi-ellipsoidal geometry. The forward tapered surface 86A of <FIG>, for example, tapers radially inward towards the axial centerline <NUM>, <NUM> as the center body <NUM> extends axially in the forward, upstream direction along the axial centerline <NUM>, <NUM> from the plateau surface 86B towards (e.g., to) the center body forward end <NUM>.

The plateau surface 86B may have a cylindrical geometry. The plateau surface 86B of <FIG>, for example, extends axially between and to the forward tapered surface 86A and the center body aft end <NUM> without, for example, significant (or any) radial displacement. More particularly, a radius from the axial centerline <NUM>, <NUM> to the plateau surface 86B may remain substantially or completely constant as the plateau surface 86B extends axially along the axial centerline <NUM>, <NUM>. The plateau surface 86B may thereby be non-radially tapered. The present disclosure, of course, is not limited to such an exemplary center body configuration. Furthermore, in other embodiments, the center body <NUM> may be omitted.

Referring to <FIG>, the fixed structure <NUM> is configured to form at least a forward portion the inlet duct <NUM> (see <FIG> and <FIG>). Briefly, referring to <FIG> and <FIG>, an aft portion of the inlet duct <NUM> may be formed by the outer case <NUM>. However, in other embodiments, the fixed structure <NUM> may form an entirety of the inlet duct <NUM> where, for example, the gas turbine engine <NUM> is configured as a turbojet engine without the bypass flowpath <NUM>. Referring again to <FIG>, the fixed structure <NUM> includes a tubular inner barrel <NUM> and a tubular outer barrel <NUM>.

The inner barrel <NUM> extends circumferentially about (e.g., completely around) the axial centerline <NUM>, <NUM>. The inner barrel <NUM> extends axially along the axial centerline <NUM>, <NUM> between a forward, upstream end <NUM> of the inner barrel <NUM> and an aft, downstream end <NUM> of the inner barrel <NUM>. The inner barrel aft end <NUM> of <FIG> is connected to a forward, upstream end of the outer case <NUM>. The inner barrel <NUM> may be configured to attenuate noise generated during aircraft propulsion system operation and, more particularly for example, noise generated by rotation of the fan rotor. The inner barrel <NUM> of <FIG>, for example, may include at least one tubular noise attenuating acoustic panel <NUM> or a circumferential array of arcuate noise attenuating acoustic panels <NUM> (see dashed lines) arranged around the axial centerline <NUM>, <NUM>. The present disclosure, however, is not limited to such an acoustic inner barrel configuration.

The outer barrel <NUM> extends circumferentially about (e.g., completely around) the axial centerline <NUM>, <NUM>. The outer barrel <NUM> extends axially along the axial centerline <NUM>, <NUM> between a forward, upstream end <NUM> of the outer barrel <NUM> and an aft, downstream end <NUM> of the outer barrel <NUM>. The outer barrel aft end <NUM> of <FIG> is disposed next to respective (e.g., forward, upstream) ends of a pair of fan cowls of the outer nacelle structure <NUM>.

The outer barrel <NUM> of <FIG> includes a tubular forward segment <NUM> and a tubular aft segment <NUM>. The outer barrel forward segment <NUM> is located at the outer barrel forward end <NUM>. The outer barrel aft segment <NUM> is located at the outer barrel aft end <NUM>. The outer barrel forward segment <NUM> is separated from the outer barrel aft segment <NUM> by an annular gap. More particularly, the gap extends axially aft and radially out from a trailing edge <NUM> of the outer barrel forward segment <NUM> to a leading edge <NUM> of the outer barrel aft segment <NUM>. This gap forms an entrance of a receptacle <NUM> (e.g., an annular cavity) for the moveable structure <NUM> (see <FIG>) in the fixed structure <NUM>. This receptacle <NUM> projects axially along the axial centerline <NUM>, <NUM> partially into the fixed structure <NUM> from the annular receptacle entrance. The receptacle <NUM> is located radially between the inner barrel <NUM> and the outer barrel <NUM>. The receptacle <NUM> of <FIG> extends circumferentially about (e.g., completely around) the centerline <NUM>, <NUM> within the fixed structure <NUM>.

Referring to <FIG>, the moveable structure <NUM> includes a tubular inlet lip structure <NUM> and a tubular deflector <NUM>. The moveable structure <NUM> of <FIG> also includes one or more pylons <NUM>; e.g., struts, bridges, support structures, etc..

The inlet lip structure <NUM> forms a leading edge <NUM> of the nacelle <NUM> (see <FIG>) as well as an outer peripheral boundary of the inner airflow inlet passage <NUM>. The inlet lip structure <NUM> of <FIG> has a cupped (e.g., a generally V-shaped or U-shaped) side sectional geometry when viewed, for example, in a plane parallel with and/or coincident with the axial centerline <NUM>, <NUM>. The inlet lip structure <NUM> and its cupped side sectional geometry extend circumferentially about (e.g., completely around) the axial centerline <NUM>, <NUM>. The inlet lip structure <NUM> of <FIG>, for example, includes axially overlapping inner and outer lip portions <NUM> and <NUM>. The inner lip portion <NUM> is connected to and may be integral with the outer lip portion <NUM> at and along the nacelle leading edge <NUM>. An aft, downstream end <NUM> of the inner lip portion <NUM> is located at (e.g., on, adjacent or proximate) an aft, downstream end <NUM> of the inlet lip structure <NUM>. An aft, downstream end <NUM> of the outer lip portion <NUM> is also located at the lip structure aft end <NUM>.

Referring to <FIG>, the inlet lip structure <NUM> includes an end surface <NUM> with one or more end surface segments <NUM>. These end surface segments <NUM> are arranged circumferentially about the axial centerline <NUM>, <NUM> in an (e.g., annular) array. Each of the end surface segments <NUM> is arranged between a respective circumferentially neighboring pair of the pylons <NUM>. Each of the end surface segments <NUM> of <FIG>, for example, is an arcuate surface segment that extends circumferentially about the axial centerline <NUM>, <NUM> between and to the respective circumferentially neighboring pair of the pylons <NUM>.

Referring to <FIG>, each of the end surface segment <NUM> may be configured to provide the lip structure aft end <NUM> with a tapered geometry. Each end surface segment <NUM> of <FIG>, for example, has a curved (e.g., a concave) sectional geometry when viewed, for example, in a plane parallel with and/or coincident with the axial centerline <NUM>, <NUM>. This curved end surface segment <NUM> tapers radially inwards as the respective end surface segment <NUM> extends axially in an aft, downstream direction from the aft end <NUM> of the outer lip portion <NUM> to the aft end <NUM> of the inner lip portion <NUM>.

The deflector <NUM> extends axially along the axial centerline <NUM>, <NUM> between and to a forward, upstream end <NUM> (e.g., a leading edge <NUM>) of the deflector <NUM> and an aft, downstream end <NUM> of the deflector <NUM>. The deflector <NUM> extends circumferentially about (e.g., completely around) the axial centerline <NUM>, <NUM>. The deflector <NUM> extends radially between and to an inner (e.g., interior) side <NUM> of the deflector <NUM> and an outer (e.g., exterior) side <NUM> of the deflector <NUM>.

Referring to <FIG>, the deflector outer side <NUM> is configured with a partially tapered geometry. The deflector <NUM> of <FIG>, for example, includes a plurality of outer (e.g., exterior) surfaces 144A and 144B located at the deflector outer side <NUM>. The forward, upstream tapered surface 144A is located at the deflector forward end <NUM> / the deflector leading edge <NUM>. The plateau surface 144B is located at the deflector aft end <NUM>.

The forward tapered surface 144A may have a frustoconical geometry (e.g., the surface may have a straight sectional geometry), or another tapered geometry such as a frusto-ellipsoidal geometry (e.g., the surface may have partially elliptical or otherwise (e.g., convex) curved sectional geometry). The forward tapered surface 144A of <FIG>, for example, tapers radially inward towards the axial centerline <NUM>, <NUM> as the deflector <NUM> extends axially in the forward, upstream direction along the axial centerline <NUM>, <NUM> from the plateau surface 144B towards (e.g., to) the deflector forward end <NUM> / the deflector leading edge <NUM>.

The plateau surface 144B may have a cylindrical geometry. The plateau surface 144B of <FIG>, for example, extends axially between and to the forward tapered surface 144A and the deflector aft end <NUM> without, for example, significant (or any) radial displacement. More particularly, a radius from the axial centerline <NUM>, <NUM> to the plateau surface 144B may remain substantially or completely constant as the plateau surface 144B extends axially along the axial centerline <NUM>, <NUM>. The plateau surface 144B may thereby be non-radially tapered. The present disclosure, of course, is not limited to such an exemplary deflector configuration.

The deflector inner side <NUM> of <FIG> is configured with a non-tapered geometry. The deflector <NUM> of <FIG>, for example, includes an inner (e.g., interior) surface <NUM> located at the deflector inner side <NUM>. This inner surface may have a cylindrical geometry. The inner surface <NUM> of <FIG>, for example, extends axially between and to the deflector forward end <NUM> and the deflector aft end <NUM> without, for example, significant (or any) radial displacement. More particularly, a radius from the axial centerline <NUM>, <NUM> to the inner surface <NUM> may remain substantially or completely constant as the inner surface <NUM> extends axially along the axial centerline <NUM>, <NUM>. The inner surface <NUM> may thereby be non-radially tapered. The present disclosure, of course, is not limited to such an exemplary deflector configuration.

Referring to <FIG>, the pylons <NUM> are configured to structurally tie the inlet lip structure <NUM> and the deflector <NUM> together. The pylons <NUM> of <FIG>, for example, are arranged circumferentially about the axial centerline <NUM>, <NUM> in an array. Each of the pylons <NUM> extends axially between and to the lip structure aft end <NUM> and the deflector forward end <NUM>. Each of the pylons <NUM> is connected to (e.g., fixedly, structurally tied to) the inlet lip structure <NUM> and the deflector <NUM>.

Each of the pylons <NUM> extends laterally (e.g., circumferentially or tangentially) between opposing circumferential sides <NUM> of the respective pylon <NUM>. Each of the pylons <NUM> extends radially between and to an inner (e.g., interior) side <NUM> of the respective pylon <NUM> and an outer (e.g., exterior) side <NUM> of the respective pylon <NUM>.

Each of the pylons <NUM> includes an outer (e.g., exterior) surface <NUM> located at the respective pylon outer side <NUM>. This pylon outer surface <NUM> may have a polygonal shape such as, but not limited to, a (e.g., isosceles) trapezoidal shape; however, the present disclosure is not limited thereto. Each pylon outer surface <NUM> may be configured to follow common lines as the outer surfaces 144A and <NUM>. The outer surfaces 144A, <NUM> and <NUM> of <FIG>, for example, may collectively form a single aerodynamic exterior surface of the moveable structure <NUM>; e.g., a surface with a common or continuous profile.

The pylons <NUM> are spaced about the axial centerline <NUM>, <NUM> to provide the moveable structure <NUM> with one or more ports <NUM>. Each of these ports <NUM> extends radially through a tubular sidewall of the moveable structure <NUM>. Each port <NUM> of <FIG>, for example, extends radially through the moveable structure <NUM> from the outer surfaces 144A, <NUM> and <NUM> to an inner surface <NUM> of the inlet lip structure <NUM>. Each port <NUM> extends axially within the moveable structure <NUM> from the lip structure aft end <NUM> to the deflector forward end <NUM>. Each port <NUM> extends circumferentially within the moveable structure <NUM> between and to respective sides <NUM> of a circumferentially neighboring pair of the pylons <NUM>.

Referring to <FIG>, the moveable structure <NUM> is mated with the fixed structure <NUM>. An aft end portion of the moveable structure <NUM> of <FIG>, for example, is arranged within the receptacle <NUM>. The moveable structure <NUM> of <FIG> is further moveably coupled with the fixed structure <NUM>. The moveable structure <NUM>, for example, may include one or more sliders <NUM>, where each slider <NUM> is mated with and configured to slide axially along a respective track <NUM> within the receptacle <NUM>. Each of the sliders <NUM> may be configured as an extension of a respective one of the pylons <NUM>, or otherwise fixed to the moveable structure <NUM>. With this configuration, the moveable structure <NUM> is configured to move axially along the axial centerline <NUM>, <NUM> between an aft (e.g., retracted, fully closed) position (see <FIG>) and a forward (e.g., extended, fully open) position (see <FIG>). Note, while the centerline <NUM> and <NUM> are shown as co-axial in the drawings, the present disclosure is not limited thereto. For example, in other embodiments, the centerlines <NUM> and <NUM> may be radially offset and/or angularly offset by an angle; e.g., an acute angle.

At the aft position of <FIG> and <FIG>, the lip structure aft end <NUM> is abutted axially against a forward end <NUM> of the fixed structure <NUM>. The inlet lip structure <NUM> of <FIG>, for example, may axially engage the fixed structure <NUM> through a seal element <NUM> such as, but not limited to, a gasket. Referring to <FIG>, with this arrangement, each of the ports <NUM> (see <FIG>) is covered and thereby closed by a respective portion of the fixed structure <NUM> and its outer surface. An aft end portion of the deflector <NUM> is stowed (e.g., received) within the receptacle <NUM>. Referring to <FIG>, an aft end <NUM> of the forward tapered surface 144A may be axially aligned with the forward end <NUM> of the outer barrel aft segment <NUM>, and the deflector forward end <NUM> may be axially aligned with the aft end <NUM> of the outer barrel forward segment <NUM>. The deflector leading edge <NUM> of <FIG> may be radially engaged with (e.g., contacting) or otherwise in close proximity with the fixed structure <NUM> and its forward segment <NUM>.

At the forward position of <FIG> and <FIG>, the lip structure aft end <NUM> is axially displaced from the fixed structure forward end <NUM>. With this arrangement, each of the ports <NUM> is uncovered by the fixed structure <NUM> and its outer surface and thereby opened. These open ports <NUM> collectively provide the outer airflow inlet passage <NUM> to the inlet duct <NUM>. In addition, referring to <FIG>, the deflector leading edge <NUM> / the deflector forward end <NUM> is located at (e.g., on, adjacent or proximate) the fixed structure forward end <NUM>. The deflector leading edge <NUM> of <FIG>, for example, is substantially axially aligned with the fixed structure forward end <NUM>. The deflector leading edge <NUM> and, more generally, the deflector <NUM> is also radially displaced (e.g., spaced) from the fixed structure <NUM> at its forward end <NUM> by a (e.g., annular) blind cavity <NUM>. This cavity <NUM> extends radially between and is formed by the fixed structure <NUM> and the deflector <NUM>. The cavity <NUM> projects axially into the variable area inlet <NUM> to an (e.g., sealed) interface <NUM> between the fixed structure <NUM> and the deflector <NUM>. The cavity <NUM> is thereby a sealed cavity in that air (e.g., only) enters and leaves the cavity <NUM> from the same forward (e.g., annular) orifice. The deflector <NUM> may thereby provide the variable area inlet <NUM> with a virtual ramp into the outer airflow inlet passage <NUM> as described below in further detail.

Referring to <FIG> and <FIG>, the center body <NUM> is fixedly connected to the fixed structure <NUM>. The center body <NUM> of <FIG> and <FIG>, for example, is structurally tied to the fixed structure <NUM> by one or more struts <NUM>.

With the foregoing configuration, the variable area inlet components <NUM>, <NUM> and <NUM> are configured as a valve <NUM>. This valve <NUM> is configured to regulate the flow of air through at least the outer airflow inlet passage <NUM> to the inlet duct <NUM>. For example, in the aft position of <FIG>, the valve <NUM> is configured to (e.g., fully, completely) close the outer airflow inlet passage <NUM> (see <FIG>). The valve <NUM> may thereby fluidly decouple the outer airflow inlet passage <NUM> from the inlet duct <NUM>. However, in the forward position of <FIG>, the valve <NUM> is configured to (e.g., fully, completely) open the outer airflow inlet passage <NUM>. The valve <NUM> may thereby fluidly couple the outer airflow inlet passage <NUM> with the inlet duct <NUM>. While the moveable structure <NUM> is described above as moving (e.g., axially translating) between its aft position (see <FIG>) and its forward position (see <FIG>), it is contemplated the moveable structure <NUM> may also move to one or more intermediate positions axially therebetween in order to variably modulate / regulate the flow of air through the outer airflow inlet passage <NUM> to the inlet duct <NUM>.

In addition to providing an additional pathway to for air to enter the inlet duct <NUM>, the variable area inlet <NUM> of the present disclosure also includes the deflector <NUM> to direct the air into the outer airflow inlet passage <NUM>. At the forward position of <FIG> during flight, the deflector <NUM> provides the virtual ramp (e.g., ram air scoop) into the outer airflow inlet passage <NUM>. The deflector <NUM> of <FIG>, for example, is configured to protrude radially into boundary layer air traveling along the variable area inlet <NUM>. The deflector <NUM> thereby impedes continued aft flow of the boundary layer air, and redirects that boundary layer air into the outer airflow inlet passage <NUM>. Because the cavity <NUM> between the deflector <NUM> and the fixed structure <NUM> is blind (e.g., there is only one opening into / out of the cavity <NUM>), air is pressurized within the cavity <NUM>. This pressurized air impedes flow of additional air into the cavity <NUM>. The pressurized air within the cavity <NUM> may thereby functionally create a high pressure air wall radially between the deflector <NUM> and the fixed structure <NUM> so that the air redirected by the deflector <NUM> enters the outer airflow inlet passage <NUM>. The deflector <NUM> and its virtual ramp may thereby increase airflow into the outer airflow inlet passage <NUM>. By contrast, if the deflector <NUM> was omitted as shown in <FIG>, boundary layer air is more likely to skip past inlet <NUM> to outer airflow inlet passage <NUM>. Referring now to <FIG>, the deflector <NUM> may also increase airflow into the outer airflow inlet passage <NUM> when, for example, the aircraft is on the runway by facilitating air turning and thereby minimizing separation along inner surface <NUM>.

<FIG> illustrate a sequence of the moveable structure <NUM> moving (e.g., translating) axially along the axial centerline <NUM>, <NUM> from the aft (e.g., retracted, closed) position to the forward (e.g., extended, open) position. As illustrated, the deflector <NUM> is configured to move axially with the inlet lip structure <NUM>. Furthermore, the deflector <NUM> of <FIG> may be configured to maintain a constant radial distance from the axial centerline <NUM>, <NUM> to the deflector leading edge <NUM>. In other words, the deflector <NUM> may only move axially as the moveable structure <NUM> moves form the aft position to the forward position.

In addition to regulating air flow through the outer airflow inlet passage <NUM>, the variable area inlet <NUM> of <FIG> and <FIG> may also regulate air flow through the inner airflow inlet passage <NUM>. For example, the inlet lip structure <NUM> may be arranged with the center body <NUM> such that a (e.g., minimum) radial distance <NUM> from the center body <NUM> to the inlet lip structure <NUM> at a choke point therebetween changes as the inlet lip structure <NUM> moves axially along the centerline <NUM>, <NUM>. For example, at the aft position of <FIG>, the radial distance <NUM> may have a first value. At the forward position of <FIG>, the radial distance <NUM> may have a second value that is different (e.g., greater) than the first value. The variable area inlet <NUM> may thereby further increase airflow into the inlet duct <NUM> by increasing a size of the inner airflow inlet passage <NUM>. Of course, in other embodiments, the variable area inlet <NUM> may be configured such that the inner airflow inlet passage <NUM> is a fixed area passage.

Referring to <FIG>, each of the ports <NUM> has a cross-sectional geometry when viewed, for example, in a plane perpendicular to a longitudinal axis of the respective port <NUM>. This cross-sectional geometry may be polygonal, or another shape. For example, referring to <FIG>, the cross-sectional geometry may be rectangular. Referring to <FIG>, the cross-sectional geometry may be (e.g., isosceles or asymmetrical) trapezoidal. Referring to <FIG>, the cross-sectional geometry may be (e.g., isosceles or asymmetrical) triangular. Where the port <NUM> is tapered, the port <NUM> may taper in the forward, upstream direction as shown, for example, in <FIG>. Alternatively, the port <NUM> may taper in the aft, downstream direction as shown, for example, in <FIG>. Tapering the port <NUM> may facilitate tuning of how fast and when additional air flows through the outer airflow inlet passage <NUM> as the moveable structure <NUM> moves between its aft and forward positions.

The aircraft propulsion system inlet structure <NUM> may be configured as a non-scarfed inlet structure or as a scarfed inlet structure. The term "non-scarfed" may describe an inlet structure where a plane defined by its leading edge (e.g., <NUM> in <FIG>) is perpendicular to the axial centerline <NUM>, <NUM>. The term "scarfed" may describe an inlet structure where the plane defined by its leading edge (e.g., <NUM> in <FIG>) is angularly offset from the axial centerline <NUM>, <NUM> an acute angle <NUM>.

The aircraft propulsion system inlet structure <NUM> and its components (e.g., <NUM>, <NUM>) may extend circumferentially completely around the axial centerline <NUM>, <NUM>. Alternatively, the aircraft propulsion system inlet structure <NUM> and/or any one or more of its components (e.g., <NUM>, <NUM>) may extend partially circumferentially around the axial centerline <NUM>, <NUM> such that the inner airflow inlet passage <NUM> is partially annular (e.g., with the center body <NUM>), or partially circular, partially elliptical, etc. (e.g., without the center body <NUM>). In still other embodiments, the aircraft propulsion system inlet structure <NUM> may be configured with a polygonal (e.g., rectangular) inner airflow inlet passage <NUM> and/or outer airflow passage <NUM>. The present disclosure, of course, is not limited to the exemplary passage <NUM>, <NUM> geometries described above.

The aircraft propulsion system <NUM> and its variable area inlet <NUM> may be configured with various gas turbine engines other than the one described above. The gas turbine engine, for example, may be configured as a geared or a direct drive turbine engine. The gas turbine engine may be configured with a single spool, with two spools (e.g., see <FIG>), or with more than two spools. The gas turbine engine may be configured as a turbofan engine, a turbojet engine or any other type of turbine engine. The present invention therefore is not limited to any particular types or configurations of gas turbine engines. The present disclosure is also not limited to applications where the aircraft is capable of traveling supersonic speeds.

Claim 1:
An assembly (<NUM>) for an aircraft propulsion system (<NUM>), comprising:
a variable area inlet (<NUM>) comprising a fixed structure (<NUM>) and a moveable structure (<NUM>), the variable area inlet (<NUM>) configured to open and close an airflow inlet passage (<NUM>) into the aircraft propulsion system (<NUM>);
the moveable structure (<NUM>) configured to move axially along a centerline (<NUM>, <NUM>) between an aft position and a forward position, and the moveable structure (<NUM>) comprising an inlet lip structure (<NUM>) and a deflector (<NUM>);
wherein, when the moveable structure (<NUM>) is in the aft position, the airflow inlet passage (<NUM>) is closed, and the deflector (<NUM>) is at least partially recessed into the fixed structure (<NUM>); and
wherein, when the moveable structure (<NUM>) is in the forward position, the airflow inlet passage (<NUM>) is opened axially between an aft end (<NUM>) of the inlet lip structure (<NUM>) and a forward end (<NUM>) of the fixed structure (<NUM>), and a forward end (<NUM>) of the deflector (<NUM>) is disposed axially at the forward end (<NUM>) of the fixed structure (<NUM>),
characterised in that:
a blind cavity (<NUM>) projects axially partially into the variable area inlet (<NUM>) when the moveable structure (<NUM>) is in the forward position; and
the blind cavity (<NUM>) extends radially between the deflector (<NUM>) and the fixed structure (<NUM>) when the moveable structure (<NUM>) is in the forward position.