Patent Description:
An aircraft propulsion system includes 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 structure with a variable airflow inlet area.

<CIT> discloses a prior art air intake unit for an engine of an aircraft.

<CIT> discloses a prior art system and method for ectively changing an effective flow-through area of an inlet region of an aircraft engine.

<CIT> discloses a prior art hybrid aircraft intake system. <CIT> discloses a prior art aircraft engine leading edge auxiliary air inlet.

<CIT> discloses a prior art rotatable scarf inlet for an aircraft engine and a method of using the same.

<CIT> discloses a prior art air intake duct for a gas turbine engine.

According to an aspect of the present disclosure, there is provided an assembly for an aircraft propulsion system as recited in claim <NUM>.

<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>; i.e., 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>; i.e., an inner nacelle structure, which may also be referred to as an inner fixed structure. 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 a bypass flow path <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 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 inlet structure <NUM> of the outer nacelle structure <NUM>; i.e., a nacelle inlet structure. This air is directed through a duct <NUM> (e.g., a fan duct in the fan section <NUM>) and into a core flow path <NUM> and the bypass flow path <NUM>. The core flow path <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 flow path <NUM> is radially within the inner case <NUM>. The bypass flow path <NUM> extends axially along the axial centerline <NUM> within the aircraft propulsion system <NUM> to a bypass nozzle outlet, where the bypass flow path <NUM> is radially between the nacelle structures <NUM> and <NUM>. The air within the core flow path <NUM> may be referred to as "core air". The air within the bypass flow path <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. The rotation of the turbine rotor <NUM> also drives rotation of the fan rotor <NUM>, which propels bypass air through and out of the bypass flow path <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 nacelle 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, the nacelle inlet structure <NUM> may be configured to direct a first mass flow of the air into the aircraft propulsion system <NUM>. When the aircraft flies at subsonic speeds, the nacelle inlet structure <NUM> may be configured to direct a second mass flow of the air into the aircraft propulsion system <NUM>, where the second mass flow is greater than the first mass flow.

To accommodate changing mass flows, the nacelle inlet structure <NUM> of <FIG> is configured with a variable airflow inlet area. Referring to <FIG> for example, during a first (e.g., supersonic) mode of operation, the nacelle inlet structure <NUM> is configured (e.g., only) with a first inlet opening <NUM>; e.g., a primary inlet opening, an inner inlet opening, a central inlet opening and/or a fixed area inlet opening. This first inlet opening <NUM> has a (e.g., maximum) first inlet opening flow area. Referring to <FIG>, during a second (e.g., subsonic) mode of operation, the nacelle inlet structure <NUM> is configured with the first inlet opening <NUM> as well as with one or more second inlet openings <NUM>; e.g., secondary / auxiliary inlet opening(s), outer inlet opening(s) and/or variable area inlet opening(s). Each of these second inlet openings <NUM> has a (e.g., maximum) second inlet opening flow area. This second inlet flow area may be less than the first inlet opening flow area. A total flow area of the second inlet openings <NUM> may also be less than the first inlet opening flow area. The present disclosure, however, is not limited to the foregoing exemplary relationships between the first and the second inlet opening flow areas. For example, in other embodiments, the total flow area of the second inlet openings <NUM> (or the second inlet flow area of each opening <NUM>) may be equal to or greater than the first inlet opening flow area.

While the inlet openings <NUM> and <NUM> in the nacelle inlet structure <NUM> of <FIG> are discrete / fluidly isolated openings (e.g., ports), each of these inlet openings <NUM>, <NUM> may be fluidly coupled with / lead to a common duct within the aircraft propulsion system <NUM>. For example, referring to <FIG>, the first inlet opening <NUM> is fluidly coupled to an upstream end of the duct <NUM> (e.g., a fan duct, or a compressor duct in other engine application) through a first inlet opening passage <NUM>. Similarly, each second inlet opening <NUM> is fluidly coupled to the upstream end of the duct <NUM> through a respective second inlet opening passage <NUM> (see also <FIG>). The duct of <FIG> therefore is fluidly coupled in parallel with first inlet opening <NUM> and each second inlet opening <NUM>. The present disclosure, however, is not limited to such an exemplary arrangement. For example, in other embodiments, the first inlet opening <NUM> and one or more of the second inlet openings <NUM> may be fluidly coupled with different downstream ducts.

The nacelle inlet structure <NUM> of <FIG> includes a movable structure <NUM> and a static structure <NUM>; e.g., a stationary, fixed structure. The movable structure <NUM> is configured to move between a first position (e.g., fully closed position of <FIG>) and a second position (e.g., fully open position of <FIG>), where the movable structure <NUM> at least partially or completely closes one or more or all of the second inlet openings <NUM> in the first position of <FIG>, and where the movable structure <NUM> at least partially or completely opens one or more or all of the second inlet openings <NUM> in the second position of <FIG>. More particularly, the movable structure <NUM> of <FIG> is configured as a rotatable structure which rotates (e.g., partially) clockwise or counter-clockwise about a rotational axis <NUM> between the first and the second positions, which rotational axis <NUM> may be a centerline of the movable structure <NUM>, the static structure <NUM> and/or the nacelle inlet structure <NUM>. The rotational axis <NUM> of <FIG> is coaxial with the axial centerline <NUM>; however, in other embodiments the axis <NUM> and the axial centerline <NUM> may be eccentric / non-coaxial (e.g., see <FIG>). More particularly, the rotational axis <NUM> may be displaced from and/or angularly offset from the axial centerline <NUM>.

Referring to <FIG>, the movable structure <NUM> extends circumferentially about (e.g., completely around) the rotational axis <NUM>. The movable structure <NUM> extends radially between a radial inner side <NUM> and a radial outer side <NUM>. The movable structure <NUM> extends axially along the rotational axis <NUM> from a forward, upstream end <NUM> to an aft, downstream end <NUM>, where the movable structure <NUM> forms an inlet lip <NUM> of the nacelle inlet structure <NUM> at the forward, upstream end <NUM>.

The movable structure <NUM> includes an (e.g., tubular) inner surface <NUM> at the movable structure inner side <NUM>. This inner surface <NUM> extends axially along the rotational axis <NUM> from the inlet lip <NUM> towards or to the aft, downstream end <NUM>. The inner surface <NUM> thereby forms an inner bore through the movable structure <NUM>. This inner bore forms the first inlet opening passage <NUM>. The inner bore also forms an outer peripheral boundary of the first inlet opening <NUM> at the inlet lip <NUM> / the forward, upstream end <NUM>. The movable structure <NUM> thereby extends circumferentially about (e.g., circumscribes) and may completely define the first inlet opening <NUM>.

The movable structure <NUM> includes one or more outer surfaces <NUM> at the movable structure outer side <NUM>. Each of these outer surfaces <NUM> is configured to form a respective portion of an outer peripheral aerodynamic flow surface <NUM> of the nacelle inlet structure <NUM> (see <FIG>). In the embodiment of <FIG>, each outer surface <NUM> has a triangular geometry; however, the present disclosure is not limited thereto.

The movable structure <NUM> is also configured with one or more channels <NUM>; e.g., grooves, recesses, indentations, trenches, etc. The channels <NUM> are arranged on opposing sides of the movable structure <NUM>. Each of these channels <NUM> projects radially into the movable structure <NUM> from the movable structure outer side <NUM> and/or the outer surface(s) <NUM> to a channel end surface <NUM>. Each channel <NUM> extends laterally (e.g., circumferentially or tangentially) within the movable structure <NUM> between opposing channel side surfaces <NUM>. Each channel <NUM> extends axially along and through the movable structure <NUM> between a forward, upstream edge <NUM> of the channel end surface <NUM> and an aft, downstream edge <NUM> of the channel end surface <NUM>.

The channel end surface <NUM> of <FIG> extends circumferentially about the rotational axis <NUM>. The channel end surface <NUM> radially tapers inwards towards the rotational axis <NUM> as the respective channel <NUM> extends axially from the forward, upstream edge <NUM> to the aft, downstream edge <NUM>.

Each of the channel side surfaces <NUM> extends axially along the channel end surface <NUM>. Each of the channel side surfaces <NUM> projects (e.g., radially) out from the channel end surface <NUM> towards the movable structure outer side <NUM>. In the specific embodiment of <FIG>, each channel side surface <NUM> projects to an outer surface <NUM> of a support member <NUM> (e.g., flange, etc.) of the movable structure <NUM>. The support members <NUM> are configured to support movement (e.g., rotation) of the movable member relative to the static structure <NUM> (see <FIG>).

Referring to <FIG>, the static structure <NUM> extends circumferentially about (e.g., completely around) the rotational axis <NUM>. The static structure <NUM> extends radially between a radial inner side <NUM> and a radial outer side <NUM>. The static structure <NUM> extends axially along the rotational axis <NUM> from a (e.g., wavy and/or scalloped) forward, upstream edge <NUM> to an aft, downstream end <NUM>.

The forward, upstream edge <NUM> of the static structure <NUM> includes one or more concave portions <NUM> and one or more convex portions <NUM>. Each of the concave portions <NUM> is disposed and extends between respective ends of the convex portions <NUM>.

The static structure <NUM> includes an (e.g., tubular) outer surface <NUM> at the static structure outer side <NUM>. This outer surface <NUM> extends circumferentially about (e.g., completely around) the rotational axis <NUM>. The outer surface <NUM> extends axially along the rotational axis <NUM> from the forward, upstream edge <NUM> to the aft, downstream end <NUM>. The outer surface <NUM> forms another portion of the outer peripheral aerodynamic flow surface <NUM> of the nacelle inlet structure <NUM> (see <FIG>).

Referring to <FIG>, the movable structure <NUM> is mated with (e.g., partially nested into) the static structure <NUM>. For example, the support members <NUM> of the movable structure <NUM> (see <FIG>) are arranged within an inner bore of the static structure <NUM> (see <FIG>). These support members <NUM> and/or one or more other portions of the movable structure <NUM> are moveably connected to the static structure <NUM> by, for example, one or more bearing structures, track assemblies and/or other suitable slidable / movable / pivotable connectors (not shown). With this arrangement, the static structure <NUM> may extend circumferentially about (e.g., circumscribe) at least an aft, downstream portion of the movable structure <NUM>.

When the movable structure <NUM> is in its first position of <FIG>, the channels <NUM> (see <FIG>) are covered by the static structure <NUM>. The movable structure <NUM> may thereby close the channels <NUM> and, thus, the second inlet openings <NUM>. However, when the movable structure <NUM> is in its second position of <FIG>, the channels <NUM> are uncovered by the static structure <NUM>. The second inlet openings <NUM> are thereby opened in order to provide the nacelle inlet structure <NUM> and, thus, the aircraft propulsion system <NUM> with the total airflow inlet area.

In the embodiments of <FIG>, a peripheral inner boundary of each second inlet opening <NUM> is formed by a respective one of the channel end surfaces <NUM>. A peripheral outer boundary of each second inlet opening <NUM> is formed by a respective concave portion <NUM> of the forward, upstream edge <NUM>. Each second inlet opening <NUM> therefore is formed by and is radially between the movable structure <NUM> and the static structure <NUM>.

<FIG> illustrate a sequence of the movable structure <NUM> moving (e.g., rotating) from the first position of <FIG> (see also <FIG>) to the second position of <FIG> (see also <FIG>). During this movement, the channels <NUM> move (e.g., rotate) about the rotational axis <NUM> towards the concave portions <NUM> of the static structure <NUM> and, thus, are uncovered. The movable structure <NUM> thereby opens the second inlet openings <NUM> while maintaining the first inlet opening <NUM> with a fixed area.

Referring to <FIG>, the first inlet opening <NUM> is configured as a non-annular opening. The first inlet opening <NUM>, for example, is not interrupted by another body; e.g., a nose cone, cap, etc. Alternatively, in arrangements not within the wording of the claims, the first inlet opening <NUM> may be interrupted (e.g., pierced) by a center body <NUM> (e.g., a spike, a nosecone, a cap, etc.) which projects axially into or through the first inlet opening <NUM> (e.g., see <FIG>). The first inlet opening <NUM> may thereby be configured as an annular inlet opening, outside the claims.

In some embodiments, referring to <FIG>, the movable structure <NUM> may rotate ninety degrees (<NUM>°) between its first and its second positions. However, in other embodiments, the movable structure <NUM> may rotate more than ninety degrees (e.g., between ninety degrees (<NUM>°) and one-hundred and eighty degrees (<NUM>°)) between the first and the second positions. In still other embodiments, the movable structure <NUM> may rotate less than ninety degrees (e.g., between ten (<NUM>°) and ninety degrees (<NUM>°)) between the first and the second positions.

In some embodiments, referring to <FIG>, the movable structure <NUM> may rotate counter-clockwise between its first and its second positions; e.g., when looking aft, downstream along the centerline <NUM> / the axis <NUM>. However, in other embodiments, the movable structure <NUM> may rotate clockwise between the first and the second positions; e.g., when looking aft, downstream along the centerline <NUM> / the axis <NUM>.

In some embodiments, the movable structure <NUM> may be actuated by a gear drive system. In other embodiments, the movable structure <NUM> may be actuated by one or more other types of actuators such as, but not limited to, one or more worm and gear arrangements and/or one or more linear actuators arranged around a periphery of the movable structure <NUM>.

In some embodiments, the nacelle inlet structure <NUM> may be arranged (e.g., clocked about the axis <NUM> / the centerline <NUM>) such that the second inlet openings <NUM> / the concave portions <NUM> are located on lateral sides of the nacelle inlet structure <NUM>. In other embodiments, the nacelle inlet structure <NUM> may be arranged (e.g., clocked about the axis <NUM> / the centerline <NUM>) such that the second inlet openings <NUM> / the concave portions <NUM> are located on top and bottom sides of the nacelle inlet structure <NUM>.

While the nacelle inlet structure <NUM> shown in the drawings is configured with two of the second inlet openings <NUM>, the present disclosure is not limited to such an exemplary embodiment. In other embodiments, for example, the nacelle inlet structure <NUM> may include a single one of the second inlet openings <NUM>. In still other embodiments, the nacelle inlet structure <NUM> may include more than two of the second inlet openings <NUM>.

The structure <NUM> is described above as a movable structure, and the structure <NUM> is described above as a static structure. However, it is contemplated that the functionality / operation of these structures <NUM> and <NUM> may be reversed. For example, in some embodiments, the structure <NUM> may be configured as a static structure, and the structure <NUM> may be configured as a movable structure; e.g., a rotatable structure. The structure <NUM> may thereby move (e.g., rotate clockwise or counter-clockwise about the rotational axis <NUM>) between the first and the second positions to open and close the one or more second inlet openings <NUM>. In such embodiments as well as other embodiments, the inlet lip <NUM> may be formed by a static structure; e.g., the structure <NUM>.

The aircraft propulsion system <NUM> and its nacelle inlet structure <NUM> may be configured with various gas turbine engines other than the one described above. The gas turbine engine <NUM>, for example, may be configured as a geared or a direct drive turbine engine. The gas turbine engine <NUM> may be configured with a single spool, with two spools (e.g., see <FIG>), or with more than two spools. The turbine engine <NUM> 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 to traveling supersonic speeds.

Claim 1:
An assembly for an aircraft propulsion system (<NUM>), comprising:
a nacelle inlet structure (<NUM>) including an inner inlet opening (<NUM>), an outer inlet opening (<NUM>) and a rotating structure (<NUM>);
the rotating structure (<NUM>) extending circumferentially about the inner inlet opening (<NUM>); and
the rotating structure (<NUM>) configured to rotate about an axis (<NUM>) between a first position and a second position, wherein the rotating structure (<NUM>) at least partially closes the outer inlet opening (<NUM>) in the first position, and the rotating structure (<NUM>) at least partially opens the outer inlet opening (<NUM>) in the second position,
wherein the inner inlet opening (<NUM>) is formed by an inner bore of the rotating structure (<NUM>), wherein the inner inlet opening (<NUM>) is a non-annular opening,
wherein
the nacelle inlet structure (<NUM>) further includes a static structure (<NUM>) that extends circumferentially about the rotating structure (<NUM>); and
the outer inlet opening (<NUM>) is radially between the rotating structure (<NUM>) and the static structure (<NUM>).