Patent Description:
An aircraft propulsion system may include a thrust reverser system for redirecting an airflow from a generally aft direction to a generally forward direction during aircraft landing. Various types and configurations of thrust reverser systems are known in the art. While these known thrust reverser systems have various benefits, there is still room in the art for improvement. There is a need in the art therefore for an improved thrust reverser system which may, for example, increase thrust reverser system efficiency, reduce thrust reverser system size, reduce thrust reverser system weight, and/or reduce nacelle maximum diameter. Document <CIT> discloses a thrust reverser according to the prior art.

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

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

The aircraft propulsion system assembly may also include a scoop configured with the first vane. The scoop may project out from an upstream end of the first vane to the serrated leading edge.

The scoop may include a base and a plurality of protrusions. The protrusions may be arranged along an upstream end of the base. Each of the protrusions may project out from the base. The serrated leading edge may be formed at least by the protrusions.

The protrusions may include a first protrusion and a second protrusion. The first protrusion may laterally neighbor the second protrusion. The first protrusion may be laterally spaced from the second protrusion by a lateral inter-protrusion distance.

The first protrusion may have a chord length that extends from the upstream end of the base to a distal end of the first protrusion. The lateral inter-protrusion distance may be between two-third times the chord length and one and one-half times the chord length.

The serrated leading edge may also be formed by the base at the upstream end of the base.

The protrusions may have common configurations.

The protrusions may include a first protrusion. The first protrusion may have a triangular geometry.

The protrusions may include a first protrusion. The first protrusion may have a chord length and a span length. An aspect ratio of two times the span length to the chord length may be between <NUM> and <NUM>. The chord length may extend from the upstream end of the base to a distal end of the first protrusion. The span length may extend laterally along the base between opposing sides of the first protrusion at the upstream end of the base.

The protrusions may include a first protrusion. The first protrusion may have a tip, a first protrusion side and a second protrusion side that meets the first protrusion side at the tip. The first protrusion side may be angularly offset from the second protrusion side by an angle between twenty degrees and sixty degrees.

The base may have a base length that extends longitudinally along a camber line from the cascade structure to the upstream end of the base. The base length may be between two times and four times a variable X. The protrusions may include a first protrusion. The first protrusion may have a chord length that extends longitudinally along the camber line from the upstream end of the base to a distal end of the first protrusion. The chord length may be between one-third times and one times the variable X.

The protrusions may include a first protrusion and a second protrusion. The first protrusion may be laterally aligned with the first flow passage. The second protrusion may be laterally aligned with the first flow passage.

The flow passages may also include a second flow passage laterally next to the first flow passage. The protrusions may include a first protrusion and a second protrusion. The first protrusion may be laterally aligned with the first flow passage. The second protrusion may be laterally aligned with the second flow passage.

The flow passages may also include a second flow passage. The first protrusion may laterally overlap the first flow passage and the second flow passage.

The aircraft propulsion system assembly may also include a forward thrust duct. The thrust reverser system may also include a thrust reverser duct and a bullnose ramp. The cascade structure may be arranged within the thrust reverser duct. The bullnose ramp may be adapted to provide a transition from the forward thrust duct to the thrust reverser duct when the thrust reverser system is in a deployed configuration. The scoop may be connected to the bullnose ramp by one or more supports.

The cascade structure may extend axially along a centerline from a cascade structure upstream end to a cascade structure downstream end. The first flow passage may be an axially upstream-most one of the flow passages.

The serrated leading edge may extend laterally along an entirety of a lateral length of the first flow passage.

<FIG> illustrates an aircraft propulsion system <NUM> for an aircraft such as, but not limited to, a commercial airliner or a cargo plane. The propulsion system <NUM> includes a nacelle <NUM> and a gas turbine engine. This gas turbine engine may be configured as a high-bypass turbofan engine. Alternatively, the gas turbine engine may be configured as a turbojet engine or any other type of gas turbine engine capable of propelling the aircraft during flight.

The nacelle <NUM> is configured to house and provide an aerodynamic cover for the gas turbine engine. An outer structure <NUM> of the nacelle <NUM> extends axially along an axial centerline <NUM> (e.g., a centerline of the propulsion system <NUM>, the nacelle <NUM> and/or the gas turbine engine) between a nacelle forward end <NUM> and a nacelle aft end <NUM>. The nacelle outer structure <NUM> of <FIG> includes a nacelle inlet structure <NUM>, one or more fan cowls <NUM> (one such cowl visible in <FIG>) and a nacelle aft structure <NUM>, which is configured as part of or includes a thrust reverser system <NUM> (see also <FIG>).

The inlet structure <NUM> is disposed at the nacelle forward end <NUM>. The inlet structure <NUM> is configured to direct a stream of air through an inlet opening <NUM> at the nacelle forward end <NUM> and into a fan section of the gas turbine engine.

The fan cowls <NUM> are disposed axially between the inlet structure <NUM> and the aft structure <NUM>. Each fan cowl <NUM> of <FIG>, in particular, is disposed at (e.g., on, adjacent or proximate) an aft end <NUM> of a stationary portion <NUM> of the nacelle <NUM>, and extends forward to the inlet structure <NUM>. Each fan cowl <NUM> is generally axially aligned with the fan section of the gas turbine engine. The fan cowls <NUM> are configured to provide an aerodynamic covering for a fan case <NUM>.

Briefly, the fan case <NUM> extends circumferentially around the axial centerline <NUM> and thereby circumscribes the fan section. Referring to <FIG>, the fan case <NUM> along with the nacelle <NUM> form a forward outer peripheral boundary of a forward thrust duct <NUM> of the propulsion system <NUM>. In the embodiment of <FIG>, the forward thrust duct <NUM> is configured as a bypass duct. The forward thrust duct <NUM> of <FIG>, for example, at least partially or completely forms a bypass flowpath <NUM> within the propulsion system <NUM>, which bypass flowpath <NUM> bypasses (e.g., flows around and/or outside of, not through) a core of the gas turbine engine to a bypass nozzle <NUM>. Thus, during nominal propulsion system operation (e.g., when the thrust reverser system <NUM> is in its stowed configuration; see <FIG>), the forward thrust duct <NUM> is configured to facilitate forward thrust for the propulsion system <NUM>; e.g., direct fluid (e.g., fan / compressed air) out of the propulsion system <NUM> through the bypass nozzle <NUM> in an axially aft direction.

Referring again to <FIG>, the aft structure <NUM> includes a translating sleeve <NUM> for the thrust reverser system <NUM>. The translating sleeve <NUM> of <FIG> is disposed at the nacelle aft end <NUM>. This translating sleeve <NUM> extends axially along the axial centerline <NUM> between a forward end <NUM> of the translating sleeve <NUM> and the nacelle aft end <NUM>. The translating sleeve <NUM> is configured to partially form an aft outer peripheral boundary of the forward thrust duct <NUM> and its flowpath <NUM> (see <FIG>). The translating sleeve <NUM> may also be configured to form the bypass nozzle <NUM> for the bypass flowpath <NUM> with an inner structure <NUM> of the nacelle <NUM> (e.g., an inner fixed structure (IFS)), which nacelle inner structure <NUM> houses the core of the gas turbine engine. Briefly, the turbine engine core typically includes a compressor section, a combustor section and a turbine section of the gas turbine engine.

The translating sleeve <NUM> of <FIG> includes a pair of sleeve segments <NUM> (e.g., halves) arranged on opposing sides of the propulsion system <NUM> (one such sleeve segment visible in <FIG>). The present disclosure, however, is not limited to such an exemplary translating sleeve configuration. For example, the translating sleeve <NUM> may alternatively have a substantially tubular body. For example, the translating sleeve <NUM> may extend more than three-hundred and thirty degrees (<NUM>°) around the axial centerline <NUM>.

Referring to <FIG>, the translating sleeve <NUM> is an axially translatable structure. Each translating sleeve segment <NUM>, for example, may be slidably connected to one or more stationary structures (e.g., a pylon and a lower bifurcation) through one or more respective track assemblies. Each track assembly may include a rail mated with a track beam; however, the present disclosure is not limited to the foregoing exemplary sliding connection configuration.

With the foregoing configuration, the translating sleeve <NUM> may translate axially along the axial centerline <NUM> and relative to the stationary portion <NUM>. The translating sleeve <NUM> may thereby move axially between a forward stowed position (see <FIG> and <FIG>) where the thrust reverser system <NUM> is in the stowed configuration and an aft deployed position (see <FIG> and <FIG>) where the thrust reverser system <NUM> is in a deployed configuration.

In the forward stowed position of <FIG>, the translating sleeve <NUM> provides the functionality described above.

In the aft deployed position of <FIG>, the translating sleeve <NUM> opens one or more thrust reverser ducts <NUM> (one visible in the figures), where each thrust reverser duct <NUM> extends radially through the nacelle outer structure <NUM> from a thrust reverser duct inlet <NUM> to a thrust reverser duct outlet <NUM>. The thrust reverser duct inlet <NUM> is located radially adjacent the forward thrust duct <NUM> and fluidly couples the respective thrust reverser duct <NUM> with the forward thrust duct <NUM> when the thrust reverser system <NUM> is in its deployed configuration.

In the aft deployed position of <FIG>, the translating sleeve <NUM> may also uncover one or more additional components of the thrust reverser system <NUM>. The translating sleeve <NUM> of <FIG>, for example, also uncovers one or more cascade structures <NUM> (e.g., cascade halves) (one cascade structure visible in <FIG> and <FIG>). In addition, as the translating sleeve <NUM> moves from the stowed position to the deployed position, one or more blocker doors <NUM> (see <FIG> and <FIG>) arranged with the translating sleeve <NUM> may be deployed to divert the fluid (e.g., fan / compressed air) from the forward thrust duct <NUM> and its flowpath <NUM> into the one or more thrust reverser ducts <NUM> and through the cascade structure <NUM> to provide reverse thrust for the propulsion system <NUM>; e.g., direct the fluid out of the propulsion system <NUM> through the thrust reverser duct outlet <NUM> generally in an axially forward direction and/or a radially outward direction.

<FIG> is a partial side sectional illustration of an assembly <NUM> for the propulsion system <NUM> with the thrust reverser system <NUM> in its stowed configuration. <FIG> is a partial side sectional illustration of the propulsion system assembly <NUM> with the thrust reverser system <NUM> in its deployed configuration. The propulsion system assembly <NUM> of <FIG> and <FIG> includes the fan case <NUM>, a nacelle fixed structure <NUM>, the cascade structures <NUM> (one visible in <FIG> and <FIG>), the blocker doors <NUM> and the translating sleeve <NUM>.

The fixed structure <NUM> circumscribes and axially overlaps the fan case <NUM>. The fixed structure <NUM> includes one or more internal support structures <NUM> (one visible in <FIG> and <FIG>) and one or more inlet bullnose ramps <NUM> (e.g., a fan ramp fairing) for the thrust reverser system <NUM> (one visible in <FIG> and <FIG>).

The support structures <NUM> are arranged circumferentially about the axial centerline <NUM>. One of the support structures <NUM>, for example, may be arranged on one side of the propulsion system <NUM> and another one of the support structures <NUM> may be arranged on the other opposing side of the propulsion system <NUM>. Each support structure <NUM> may provide a radial support (e.g., a landing) for a respective one of the fan cowls <NUM>. Each support structure <NUM> may also or alternatively provide support for one or more components of the thrust reverser system <NUM> such as, but not limited to, a respective one of the cascade structures <NUM> and/or a respective one of the bullnose ramps <NUM>. Of course, in other embodiments, the support structures <NUM> may be combined into a single generally annular support structure.

Each support structure <NUM> of <FIG> and <FIG> may be configured as or otherwise include a structural beam; e.g., a torque box. The structural beam provides a base structure to which a respective one of the cascade structures <NUM> and/or a respective one of the bullnose ramps <NUM> may be mounted. The structural beam also provides a base structure to which one or more actuators <NUM> (e.g., hydraulic/pneumatic actuators, or electric motors, etc.) may be mounted. Briefly, the actuators <NUM> are arranged circumferentially about the axial centerline <NUM>. These actuators <NUM> are configured to move (e.g., axially translate) the translating sleeve <NUM> axially along the axial centerline <NUM> relative to the fixed structure <NUM> between the stowed position of <FIG> and the deployed position of <FIG>.

The bullnose ramps <NUM> are arranged circumferentially about the axial centerline <NUM>. One of the bullnose ramps <NUM>, for example, may be arranged on one side of the propulsion system <NUM> and another one of the bullnose ramps <NUM> may be arranged on the other opposing side of the propulsion system <NUM>. More particularly, each of the bullnose ramps <NUM> is aligned with and partially forms the inlet <NUM> into a respective one of the thrust reverser ducts <NUM>. Each bullnose ramp <NUM> of <FIG>, for example, is configured to form a forward and/or upstream boundary (e.g., forward, upstream axial peripheral side) of the respective thrust reverser duct inlet <NUM>. Each bullnose ramp <NUM> of <FIG> is thereby also configured to provide a (e.g., smooth and/or aerodynamic) transition from the forward thrust duct <NUM> to the respective thrust reverser duct <NUM> when the thrust reverser system <NUM> is in its deployed configuration.

Each bullnose ramp <NUM> of <FIG> extends circumferentially about the axial centerline <NUM> between and to opposing circumferential ends <NUM>. Each bullnose ramp <NUM> extends axially along the axial centerline <NUM> between and to a bullnose ramp first (e.g., forward and/or upstream) side and/or edge <NUM> and a bullnose ramp second (e.g., aft and/or downstream) side and/or edge <NUM>. Each bullnose ramp <NUM> includes a bullnose ramp surface <NUM> (e.g., a transition surface) at a radial inner side of the respective bullnose ramp <NUM>. This bullnose ramp surface <NUM> is configured to provide a smooth aerodynamic transition from the forward thrust duct <NUM> to the respective thrust reverser duct <NUM> (see <FIG>). The bullnose ramp surface <NUM> of <FIG> is thereby configured with an eased, ramped and/or otherwise flared sectional geometry. The bullnose ramp surface <NUM> of <FIG>, for example, is configured with curved (e.g., arcuate) and/or splined sectional geometry when viewed, for example, in a plane parallel and/or coincident with the axial centerline <NUM>; e.g., plane of <FIG>.

Referring to <FIG>, when the thrust reverser system <NUM> is in its deployed configuration (e.g., the blocker doors <NUM> and the translating sleeve <NUM> are deployed as shown in <FIG>), fluid (e.g., fan and/or compressed air) may be directed out of the forward thrust duct <NUM> and into each thrust reverser duct <NUM>. Under certain conditions and/or with certain bullnose ramp surface geometries, boundary layer fluid <NUM> flowing along each bullnose ramp surface <NUM> may separate from the respective bullnose ramp <NUM>. As a result, very little fluid may flow into and through forward and/or upstream flow passages 92A-C (e.g., airflow channels) in the respective cascade structure <NUM>; see also <FIG>.

Referring to <FIG>, to increase fluid flow into at least one or more forwardmost and/or upstream-most flow passages 92A (one visible in <FIG>; see also <FIG>), the thrust reverser system <NUM> is configured with one or more fluid scoops <NUM> (e.g., turning vane structures, extended cascade vanes, etc.) for each respective cascade structure <NUM>. Each fluid scoop <NUM> is configured to direct a first stream <NUM> of the fluid through an arcuate scoop passage <NUM> and into the forwardmost / upstream-most flow passages 92A, where the scoop passage <NUM> is formed between a first (e.g., forward and/or upstream) surface <NUM> of the respective fluid scoop <NUM> and a portion of the bullnose ramp surface <NUM>.

Referring to <FIG>, each fluid scoop <NUM> of <FIG> also includes a serrated (e.g., sawtooth, castellated, wavy, etc.) leading edge <NUM>. This serrated leading edge <NUM> is formed at least by a plurality of protrusions <NUM>; e.g., projections, extensions, fingers, etc. Each of the protrusions <NUM> may be configured as a delta wing vortex generator. The protrusions <NUM>, for example, are operable to interact with a second stream <NUM> of the fluid (see <FIG>) passing by the serrated leading edge <NUM>. This interaction, referring to <FIG> and <FIG>, may cause vortices to form within the second stream <NUM> of the fluid, and cause the second stream <NUM> of the fluid to flow generally along a second (e.g., aft and/or downstream) surface <NUM> of the fluid scoop <NUM> and into one or more of the flow passages (e.g., 92B and/or 92C) which are (e.g., immediately) aft and/or downstream of the fluid scoop <NUM>. More particularly, the protrusions <NUM> may aid in a mixing process within the second stream <NUM> of the fluid as well as increase momentum of the low velocity flow near the scoop second surface <NUM> to resist shear forces.

By increasing mass flow into the upstream flow passages (e.g., 92A-C), the fluid scoop <NUM> and its serrated leading edge <NUM> may increase efficiency of a forward and/or upstream portion of the thrust reverser system <NUM>. The fluid scoop <NUM> and its serrated leading edge <NUM> may consequently also facilitate an overall increase in negative thrust (stopping force) of the thrust reverser system <NUM>. An axial length of the thrust reverser system <NUM> and one or more or all of its components may therefore be shortened, for example, compared to a thrust reverser system without the fluid scoop <NUM> as well as compared to a thrust reverser system with a fluid scoop but without the serrated leading edge <NUM>. Shortening the thrust reverser system <NUM> may provide for more compact thrust reverser packaging and/or reduction in thrust reverser system weight. In addition, the provision of the fluid scoop <NUM> with its serrated leading edge <NUM> may also provide for an improved area match between an effective area of the thrust reverser system <NUM> and an effective area of the bypass nozzle <NUM>.

Each cascade structure <NUM> may include one or more cascade baskets <NUM> (e.g., lateral cascade segments) arranged, for example, in an arcuate array about the axial centerline <NUM>. Referring to <FIG>, each cascade basket <NUM> extends axially along the axial centerline <NUM> between and to a first (e.g., forward and/or upstream) end <NUM> and a second (e.g., aft and/or downstream) end <NUM>. Each cascade basket <NUM> extends laterally (e.g., circumferentially or tangentially) between and to opposing sides 116A and 116B (generally referred to as "<NUM>"). Each cascade basket <NUM> extends vertically (e.g., radially) between and to a first (e.g., radial inner and/or upstream) side <NUM> and a second (e.g., radial outer and/or downstream) side <NUM>.

Each cascade basket <NUM> of <FIG> includes a base cascade structure <NUM> and one or more attachments <NUM> and <NUM>; e.g., mounting structures. Each of these attachments <NUM> and <NUM> is configured to attach / mount the cascade basket <NUM> and, thus, the respective cascade structure <NUM> to another structure of the propulsion system <NUM> such as, but not limited to, the structural beam (e.g., the torque box) or an aft cascade ring (see <FIG>). The attachments <NUM> and <NUM> of <FIG>, for example, are configured as attachment flanges with apertures for receiving fasteners; e.g., bolds, rivets, etc. The first (e.g., forward and/or upstream) attachment <NUM> is arranged at the cascade structure first end <NUM>. The second (e.g., aft and/or downstream) attachment <NUM> is arranged at the cascade structure second end <NUM>.

The base cascade structure <NUM> includes a plurality of strongback rails <NUM> and one or more arrays of cascade vanes. The strongback rails <NUM> of <FIG> are arranged parallel with one another. The strongback rails <NUM> are connected to the attachments <NUM> and <NUM>. The strongback rails <NUM> of <FIG>, for example, extend axially along the axial centerline <NUM> between and to the cascade attachments <NUM> and <NUM>.

The arrays of cascade vanes are respectively arranged between laterally adjacent strongback rails <NUM>. Each of the arrays of cascade vanes includes a plurality of the cascade vanes 130A-K (generally referred to as "<NUM>"), which are disposed at discrete locations along the axial length of the strongback rails <NUM>. Each axially adjacent pair of vanes <NUM> thereby forms a respective one of the flow passages 92B-K therebetween. Similarly, each forwardmost and/or upstream-most cascade vane 130A forms a respective one of the upstream-most flow passages 92A with the first attachment <NUM>. Each aftmost and/or downstream-most cascade vane <NUM> forms a respective one of the aftmost and/or downstream-most flow passages <NUM> with the second attachment <NUM>.

Each of the cascade vanes <NUM> is connected to a respective adjacent set of the strongback rails <NUM>. Each cascade vane <NUM> of <FIG>, for example, extends laterally between and to a respective adjacent set of the strongback rails <NUM>.

Referring to <FIG>, each of the cascade vanes <NUM> may have a non-linear (e.g., curved) cross-sectional geometry in order to redirect air flowing through the cascade structure <NUM> in the axial direction. Each cascade vane (e.g., 130A, 130B) of <FIG>, for example, extends longitudinally along a (e.g., curved) camber line (e.g., 132A, 132B; generally referred to as "<NUM>") between and to a first (e.g., radial inner and/or upstream) end (e.g., 134A, 134B; generally referred to as "<NUM>") and a second (e.g., radial outer and/or downstream) end (e.g., 136A, 136B; generally referred to as "<NUM>"), which thereby defines a cascade vane length (e.g., 138A, 138B; generally referred to as "<NUM>") longitudinally along the camber line <NUM>. The first end <NUM> of each of the cascade vanes 130B-<NUM> (see also <FIG>) may define a leading edge of that vane. The second end <NUM> of each of the cascade vanes 130A-K (see also <FIG>) may define a trailing edge of that vane.

Each fluid scoop <NUM> may be connected to one or more of the cascade vanes <NUM> (e.g., the upstream-most cascade vanes 130A) of a respective cascade basket <NUM>. Each fluid scoop <NUM> of <FIG>, for example, is formed as an integral part of the upstream-most cascade vanes 130A of a respective cascade basket <NUM>; e.g., the fluid scoop <NUM> and the upstream-most cascade vanes 130A may be formed together as a monolithic body. The fluid scoop <NUM> may thereby be configured as an upstream extension of the upstream-most cascade vanes 130A such that, for example, the components <NUM> and 130A collectively provide a continuous, extended cascade vane / turning vane. More particularly, a second (e.g., radial outer and/or downstream) end <NUM> of the fluid scoop <NUM> may be directly connected to the first end 134A of each cascade vane 130A. Each fluid scoop <NUM> may thereby extend longitudinally along the camber line 132A from the respective cascade vanes 130A to its serrated leading edge <NUM>.

Each fluid scoop <NUM> extends transversely between and to the scoop first surface <NUM> and the scoop second surface <NUM>. The scoop first surface <NUM> of <FIG> is configured as a concave and/or pressure side surface. The scoop first surface <NUM> of <FIG> is also a surface of the respective cascade vanes 130A. The scoop first surface <NUM> may thereby form a single, continuous aerodynamic concave and/or pressure side surface for both elements <NUM> and 130A. Similarly, the scoop second surface <NUM> of <FIG> is configured as a convex and/or suction side surface. The scoop second surface <NUM> of <FIG> is also a surface of the respective cascade vanes 130A. The scoop second surface <NUM> may thereby form a single, continuous aerodynamic convex and/or suction side surface for both elements <NUM> and 130A.

Referring to <FIG>, each fluid scoop <NUM> extends laterally along a respective cascade basket <NUM>. Each fluid scoop <NUM> of <FIG>, for example, extends laterally between and to the opposing sides 116A and 116B. The fluid scoop <NUM> of <FIG> may thereby extend laterally along and laterally overlap (e.g., an entirety of) one or more or each of the upstream-most cascade vanes 130A and one or more or each of the upstream-most flow passages 92A of a respective cascade basket <NUM>.

Referring to <FIG>, each fluid scoop <NUM> includes a fluid scoop base <NUM> and one or more of the fluid scoop protrusions <NUM>. The scoop base <NUM> extends laterally between and to the opposing sides 116A and 116B. Referring to <FIG>, the scoop base <NUM> extends transversely between and thereby forms respective portions of the scoop first surface <NUM> and the scoop second surface <NUM>. The scoop base <NUM> extends longitudinally along the camber line 132A from the scoop second end <NUM> to a first (e.g., radial inner and/or upstream) end <NUM> of the scoop base <NUM>, which thereby defines a scoop base length <NUM> (see <FIG>) longitudinally along the camber line 132A. The scoop base length <NUM> of <FIG> may be between two times (2x) and four times (4x) a variable X, which variable may be equal to the cascade vane length 138A. The present disclosure, however, is not limited to such an exemplary relationship between the scoop base length <NUM> and the variable X. For example, the scoop base length <NUM> may alternatively be less than two times (2x) the variable X or greater than four times (4x) the variable X.

The scoop protrusions <NUM> are connected to (e.g., formed integral with) the scoop base <NUM>. The scoop protrusions <NUM> are arranged laterally along the scoop base <NUM> at the base first end <NUM> in a linear array. Each of the scoop protrusions <NUM> is laterally spaced, separated from its laterally neighboring (e.g., immediately adjacent) scoop protrusions <NUM> by a lateral inter-protrusion distance <NUM>.

Referring to <FIG>, each scoop protrusion <NUM> projects longitudinally out from the scoop base <NUM> (at the base first end <NUM>) along the camber line 132A (see <FIG>) to a distal end <NUM> (e.g., a forward and/or upstream end / tip) of that respective scoop protrusion <NUM>, thereby defining a protrusion chord length <NUM> longitudinally along the camber line 132A (see <FIG>). This protrusion chord length <NUM> may be between one-third times (<NUM>/3x) and one times (1x) the variable X. The present disclosure, however, is not limited to such an exemplary relationship between the protrusion chord length <NUM> and the variable X. For example, the protrusion chord length <NUM> may alternatively be less than one-third times (<NUM>/3x) the variable X or greater than one times (1x) the variable X.

The protrusion chord length <NUM> may also be sized relative to the lateral inter-protrusion distance <NUM>. The lateral inter-protrusion distance <NUM>, for example, may be between two-third times (<NUM>/3x) and one and one-half times (<NUM>. 5x) the protrusion chord length <NUM>. The present disclosure, however, is not limited to such an exemplary relationship between the protrusion chord length <NUM> and the lateral inter-protrusion distance <NUM>. For example, the lateral inter-protrusion distance <NUM> may alternatively be less than two-third times (<NUM>/3x) the protrusion chord length <NUM> or greater than one and one-half times (<NUM>. 5x) the protrusion chord length <NUM>.

Each scoop protrusion <NUM> has opposing lateral protrusion sides 154A and 154B (generally referred to as "<NUM>"). These lateral protrusion sides <NUM> project out from the base first end <NUM> to, and may meet at, the protrusion distal end <NUM>. Each scoop protrusion <NUM> may thereby be configured with a triangular or otherwise tapering geometry. The lateral protrusion sides <NUM> of <FIG> are angularly offset by an included angle <NUM>. This included angle <NUM> is an acute angle such as, but not limited to, an angle between twenty degrees (<NUM>°) and sixty degrees (<NUM>°).

Each scoop protrusion <NUM> extends laterally along the scoop base <NUM> between and to its lateral protrusion sides <NUM>, thereby defining a protrusion span length <NUM> laterally along the base first end <NUM>. This protrusion span length <NUM> may be sized such that an aspect ratio of two times the protrusion span length <NUM> to the protrusion chord length <NUM> ( <MAT>) is between one (<NUM>) and two and one-half (<NUM>). The present disclosure, however, is not limited to such an exemplary aspect ratio. The aspect ratio, for example, may alternatively be less than one (<NUM>) or greater than two and one-half (<NUM>).

Referring to <FIG>, each protrusion <NUM> extends transversely between and thereby forms respective portions of the scoop first surface <NUM> and the scoop second surface <NUM>.

Referring to <FIG>, the arrangement of the scoop protrusions <NUM> along the scoop base <NUM> collectively form the serrated leading edge <NUM> of the fluid scoop <NUM>. More particularly, the lateral protrusion sides <NUM> and exposed portions <NUM> of the base first end <NUM> form a distal, peripheral boundary of the fluid scoop <NUM>, which boundary is the serrated leading edge <NUM> of the fluid scoop <NUM>.

In some embodiments, referring to <FIG>, one or more or each of the scoop protrusions <NUM> may be laterally aligned with a (e.g., single) respective one of the flow passages <NUM> (e.g., 92B). In the specific embodiment of <FIG>, each flow passage 92B is laterally aligned with a respective pair of the scoop protrusions <NUM>. However, in other embodiments, one or more or each of the flow passages <NUM> (e.g., 92B) may be laterally aligned with a single one of the scoop protrusions <NUM> or with three or more of the scoop protrusions <NUM>.

In some embodiments, referring to <FIG>, one or more of the scoop protrusions <NUM> (e.g., <NUM>') may be laterally aligned with more than one of the flow passages <NUM> (e.g., 92B). Each scoop protrusion <NUM>' of <FIG>, for example, is laterally aligned with and laterally overlaps a laterally neighboring pair of the flow passages 92B. A lateral center of each scoop protrusion <NUM>', for example, may be laterally aligned with a respective one of the strongback rails <NUM>.

In some embodiments, referring to <FIG>, the scoop protrusions <NUM> of a respective fluid scoop <NUM> may be configured with common (e.g., identical) configurations. Each of the scoop protrusions <NUM>, for example, may have an identical shape and size. The present disclosure, however, is not limited to such an exemplary scoop protrusion configuration. For example, in other embodiments, at least one of the scoop protrusions <NUM> may have a different shape and/or size than at least another one of the scoop protrusions <NUM>.

Referring to <FIG>, at a point <NUM> where the first stream <NUM> of the fluid (see <FIG>) separates from the bullnose ramp <NUM>, the fluid first stream <NUM> follows a trajectory <NUM> that is tangent to the bullnose ramp surface <NUM>. Each respective fluid scoop <NUM> at (on, adjacent or proximate) its serrated leading edge <NUM> is angularly offset from the trajectory <NUM> by an included angle <NUM>; an angle of attack of the respective scoop <NUM>. This included angle <NUM> is an acute angle such as, but not limited to, an angle greater than zero degrees (<NUM>°) and equal to or less than thirty degrees (<NUM>°); e.g., about fifteen degrees (<NUM>°).

Referring to <FIG>, each fluid scoop <NUM> is formed integral with a respective cascade structure <NUM>; e.g., a respective one of the cascade baskets <NUM>. In other embodiments not falling under the scope of the claims however, referring to <FIG>, one or more of the fluid scoops <NUM> may be discrete / separate from the cascade structure <NUM>. Each fluid scoop <NUM>, for example, may be connected to the bullnose ramp <NUM> (or another structure) by one or more supports <NUM>; e.g., struts, vanes, etc. In such embodiments, the fluid scoop <NUM> may be separated from the forward-most cascade vanes by a slight gap <NUM>.

While the gas turbine engine is generally described above as a turbofan turbine engine, the present disclosure is not limited to such an exemplary gas turbine engine configuration. For example, in other embodiments, the gas turbine engine may alternatively be configured as a turbojet gas turbine engine where, for example, the forward thrust duct <NUM> is configured as a core duct and/or an exhaust duct rather than a bypass duct. The present disclosure therefore is not limited to any particular gas turbine engine types or configurations. Furthermore, the present disclosure is not limited to a translating sleeve type thrust reverser. Rather, the cascade structures <NUM> and the fluid scoops <NUM> of the present disclosure may be configured with other types and configurations of thrust reverser systems which utilize cascades.

Claim 1:
An assembly (<NUM>) for an aircraft propulsion system (<NUM>), comprising:
a thrust reverser system (<NUM>) comprising a cascade structure (<NUM>) and a scoop (<NUM>);
the cascade structure (<NUM>) configured with a plurality of flow passages (<NUM>), each of the plurality of flow passages (<NUM>) extending through the cascade structure (<NUM>), and the plurality of flow passages (<NUM>) comprising a first flow passage (92A); and
the scoop (<NUM>) configured to direct fluid into at least the first flow passage (92A), the scoop (<NUM>) comprising a serrated leading edge (<NUM>),
wherein:
the cascade structure (<NUM>) includes a plurality of cascade vanes (<NUM>);
a boundary of each of the plurality of flow passages (<NUM>) is formed by a respective one of the plurality of cascade vanes (<NUM>); and
the scoop (<NUM>) is integral with and forms an extension of a first of the plurality of cascade vanes (<NUM>).