Thrust reverser cascade systems and methods

Systems and methods are provided for a formed thrust reverser cascade. The formed thrust reverser cascade may be coupled to an aircraft propulsor and may include a first portion disposed at a first angle to a portion of the aircraft propulsor and a second portion disposed at a second angle to the first portion. The formed thrust reverser cascade may be circumferentially disposed around a core engine of the aircraft propulsor. The formed thrust reverser cascades may be retrofitted to aircraft propulsors using linear thrust reverser cascade and may increase airflow through the formed thrust reverser cascade due to a greater throat area as compared to the linear thrust reverser cascade. Alternatively, the formed thrust reverser cascades may allow for shorter cascades while retaining the same performance, thus resulting in shorter nacelles.

TECHNICAL FIELD

The disclosure relates generally to aircrafts and more specifically to aircraft thrust reversers.

BACKGROUND

Aircraft propulsor thrust reversers often include a cascade exit area (a.k.a. throat area) where airflow may exit from within the aircraft propulsor. Traditional cascades tend to be linear. Mass flow through the cascade may increase if the cascade exit area increases. Additionally, current aircraft propulsors may benefit from lighter weight and/or more compact thrust reverser cascades.

SUMMARY

Systems and methods are disclosed herein for a formed thrust reverser cascade. In certain examples, an aircraft propulsor may be provided and may include a nacelle including a thrust reverser aperture, a thrust reverser door configured to selectively move between an open position and a closed position to selectively block the thrust reverser aperture, a core engine circumscribed by the nacelle, wherein the nacelle and the core engine define, at least in part, a bypass flow path, and a thrust reverser cascade. The thrust reverser cascade may include a plurality of cascade vanes arranged in a ramp shaped cross-section, disposed circumferentially around the core engine, and configured to couple to a portion of the nacelle and permit airflow from the bypass flow path through the cascade vanes and a connecting structure coupled to at least two of the plurality of cascade vanes. The ramp shaped cross-section may include a first section configured to be disposed at a first angle to at least a portion of a surface of the nacelle and a second section disposed at a second angle to the first section.

In certain other examples, a thrust reverser cascade may be provided. The thrust reverser cascade may include a plurality of cascade vanes arranged in a ramp shaped cross-section and configured to couple to a portion of an aircraft propulsor nacelle and permit airflow through the cascade vanes and a connecting structure coupled to at least two of the plurality of cascade vanes. The ramp shaped cross-section may include a first section configured to be disposed at a first angle to at least a portion of a surface of the aircraft propulsor nacelle, and a second section disposed at a second angle to the first section.

In certain additional examples, a method may be provided. The method may include energizing airflow with a core engine of an aircraft propulsor such that the energized airflow flows within a bypass flow path of the aircraft propulsor defined, at least in part, by the core engine and a nacelle of the aircraft propulsor, moving a thrust reverser door of the aircraft propulsor to the open position, wherein the thrust reverser door is configured to selectively move between an open position and a closed position to selectively block a thrust reverser aperture disposed within the nacelle, and diverting at least a portion of the airflow through a thrust reverser cascade. The thrust reverser cascade may include a plurality of cascade vanes arranged in a ramp shaped cross-section, disposed circumferentially around the core engine, and configured to couple to a portion of the nacelle and permit airflow from the bypass flow path through the cascade vanes and a connecting structure coupled to at least two of the plurality of cascade vanes. The ramp shaped cross-section may include a first section configured to be disposed at a first angle to at least a portion of a surface of the nacelle and a second section disposed at a second angle to the first section.

The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of the disclosure will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more implementations. Reference will be made to the appended sheets of drawings that will first be described briefly.

DETAILED DESCRIPTION

Thrust reverser cascades are described in the disclosure herein in accordance with one or more embodiments. The thrust reverser cascade may be coupled to an aircraft propulsor and may be of a shape that would increase the cascade exit area of the thrust reverser cascade. In certain examples, the thrust reverser cascade may be ramp shaped. In addition, the aircraft propulsor may include one or more thrust reverser doors that may move between the open and closed position to allow or prevent, respectively, airflow through the thrust reverser cascade. Airflow through the thrust reverser cascade may provide reverse thrust to slow an aircraft that the aircraft propulsor is coupled to.

FIG. 1Aillustrates a front view of an aircraft in accordance with an example of the disclosure.FIG. 1Aillustrates an aircraft50with a fuselage160, wings170, and aircraft propulsors100. The aircraft propulsors100may be attached to the wings170, but in other examples, the aircraft propulsors100may be attached to other portions of the aircraft50such as the fuselage160.

FIG. 1Billustrates a perspective view of an aircraft propulsor in accordance with an example of the disclosure. Aircraft propulsor100may include a nacelle102, a translating sleeve124, and a fan136. In the example shown inFIG. 1B, the nacelle102may contain the fan136, but other examples of the aircraft propulsor may arrange the fan so that the fan is not contained by the nacelle (e.g., in, for example, a turboprop configuration). The fan136may intake and/or energize air flowing into the nacelle102, such as in an airflow direction140A. Air that flows into the nacelle102via airflow direction140A may flow through various internal flow paths within the nacelle102. When the aircraft propulsor100is in a thrust reversing configuration, air that flows into the nacelle102in airflow direction140A may be redirected to another direction to provide reverse thrust.

When the aircraft propulsor100is normally operating (e.g., providing thrust), the translating sleeve124(e.g., a thrust reverser door) may be in a closed position that blocks the thrust reverser aperture (shown inFIG. 2as thrust reverser aperture132), sealing or substantially sealing the thrust reverser aperture so that there is no or minimal airflow through the thrust reverser aperture132. When the aircraft propulsor100is in a thrust reversing configuration (e.g., providing reverse thrust to, for example, slow the aircraft50that the aircraft propulsor100may attached to), the translating sleeve124may be in an open position that does not block the thrust reverser aperture132, allowing for air to flow through the thrust reverser aperture132. In certain examples, the translating sleeve124may form the thrust reverser aperture132when the translating sleeve124is in the open configuration. In such an example, there may be no thrust reverser aperture132when the translating sleeve124is in a closed configuration.

FIG. 2illustrates a side cutaway view of an aircraft propulsor in accordance with an example of the disclosure. The aircraft propulsor100shown inFIG. 2may include the nacelle102with a bullnose206, the translating sleeve124, a core engine248, a linear thrust reverser cascade210, a cascade support ring208, a thrust reverser aperture132, and a blocker door214. The core engine248and/or the nacelle102may define, at least in part, a bypass flow path256. Air energized by the fan136may flow through the bypass flow path256. During normal operations, the energized air may flow out of an exhaust of the nacelle102, but during thrust reversing, the energized air may be diverted by the blocker door213and flow out of nacelle102through the thrust reverser cascade and the thrust reverser aperture132.

The nacelle102may be similar to the nacelle described inFIG. 1B. The nacelle102inFIG. 2may additionally include the bullnose206. The bullnose206may be any structure that may couple to an end of the linear thrust reverser cascade210. In certain examples, the bullnose206may extend from another portion of the nacelle102and may form a ledge of the nacelle102. As shown inFIG. 2, at least the portion of the bullnose206facing the core engine208may include a smoothly radius'd surface. Such a radius'd surface may allow for smooth airflow from the bypass flow path256through the linear thrust reverser cascade210and, accordingly, allow for higher massflow through the linear thrust reverser cascade210. A surface of the translating sleeve124may be configured to be placed adjacent to or coupled to a portion of the bullnose206when in the closed position. As such, the translating sleeve124may, when in the closed position, form a smooth or substantially smooth surface with an interior surface of the nacelle102to allow for smooth airflow within the aircraft propulsor100when the translating sleeve124is in the closed position.

FIG. 2further illustrates the open and closed positions of the translating sleeve124. As shown, the translating sleeve124may be in an open position124B as well as a closed position124A. The translating sleeve124in other examples may be configured to be in other positions. Additionally, other examples may include non-translating thrust reverser doors (e.g., thrust reverser doors that may rotate between an open and a closed position, as well as other positions) as well as thrust reverser doors that open and close in other manners (e.g., through shutters, through the deployment of air deflectors, or through other manners).

In the closed position124A, the translating sleeve124may allow air to flow through the bypass flow path256of the aircraft propulsor100and exit the bypass flow path256through an exhaust to provide thrust. The bypass flow path256may be defined, at least in part, by portions of the core engine248and/or the nacelle102. The air flowing through the bypass flowpath256may be energized by the fan136, may generally flow in airflow direction140A, and may provide thrust (or reverse thrust) to power the aircraft that the aircraft propulsor100is attached to. The core engine248may power the fan136and the fan136may energize the air flowing through the bypass flowpath256.

When the translating sleeve124is in the closed position124A, the blocker door214may be positioned to not block or minimally block (e.g., be a restriction of less than 5% of total airflow within the bypass flow path256) airflow within the bypass flow path256.

In the open position124B, the translating sleeve124may allow air to flow through the thrust reverser aperture132. In certain examples, when the translating sleeve124is in the open position124B, the blocker door214may also be moved into a position to block at least a portion of the bypass flow path256to divert airflow within the bypass flow path256through the thrust reverser aperture132. Such diverted airflow may at least in part flow in airflow direction140B or in the general direction of airflow direction140B. Air flowing in airflow direction140B may provide reverse thrust.

Diverted airflow may flow through the linear thrust reverser cascade210. The linear thrust reverser cascade210shown inFIG. 2may be a linear thrust reverser cascade. ThoughFIG. 2shows a side cutaway view of the linear thrust reverser cascade210, the linear thrust reverser cascade210may be circumferentially disposed and/or offset from, for example, the core engine248or another portion of the aircraft propulsor100. E.g., the linear thrust reverser cascade210may “wrap around” the core engine248. Additionally, the linear thrust reverser cascade210may extend linearly, or substantially linearly, from the bullnose206to the cascade support ring208. The bullnose206and/or the cascade support ring208may be coupled to the linear thrust reverser cascade210. The bullnose206and/or the cascade support ring208may support and/or hold in place the linear thrust reverser cascade210. In certain such examples, the cascade support ring208may be attached to other structural features of the aircraft propulsor100.

FIG. 3illustrates a side cutaway view of a formed thrust reverser cascade equipped aircraft propulsor in accordance with an example of the disclosure. The formed thrust reverser cascade304may increase the cascade exit area (e.g., the “throat” area) of a thrust reverser cascade.FIG. 3illustrates the formed thrust reverser cascade304graphically overlaid over the linear thrust reverser cascade210ofFIG. 2to illustrate differences between the formed thrust reverser cascade304and the linear thrust reverser cascade210.

The formed thrust reverser cascade304may be circumferentially disposed and/or offset from the core engine248or another portion of the aircraft propulsor100. The formed thrust reverser cascade304may include a first portion disposed at a first angle to (e.g., not parallel with) at least a portion of a surface of the bullnose206and/or the cascade support ring208. The first angle may be any angle, including angles of approximately less than 20 degrees, approximately 20 to 50 degrees, approximately 50 to 90 degrees, and/or 90 degrees or more.

The formed thrust reverser cascade304may additionally include a second portion disposed at a second angle to at least the first portion. The second angle may be any angle, including angles of approximately less than 20 degrees, approximately 20 to 50 degrees, approximately 50 to 90 degrees, and/or 90 degrees or more. Accordingly the formed thrust reverser cascade304may form a “bridge” shape, as illustrated inFIGS. 3-4B, where a section of the formed thrust reverser cascade304may be raised, as compared to the linear thrust reverser cascade210. In certain such examples, at least a part of the raised portion of the formed thrust reverser cascade304may be shaped to be close to a surface of the thrust reverser door124, whether in the open or closed position, to further increase the cascade exit area. Such a configuration may be shown by the middle portion of the formed thrust reverser cascade304. In certain such examples, such a portion of the formed thrust reverser cascade304may be disposed within less than an inch, within less than five inches, within less than ten inches, within less than two feet, or within two feet or more of the thrust reverser door124.

The cascade exit area is increased, at least in part, due to the raised portion of the formed thrust reverser cascade304. The raised portion may increase the surface area of the thrust reverser cascade304as compared to a linear thrust reverser cascade of the same length. For example, as shown inFIG. 3, the formed thrust reverser cascade304and the linear thrust reverser cascade210are the same length. However, the raised portion of the formed thrust reverser cascade304may be farther from, for example, a centerline of the core engine248and/or a centerline of such a thrust reverser cascade. The formed thrust reverser cascade304and/or the linear thrust reverser cascade210may be cylindrical, substantially cylindrical, and/or partially cylindrical.FIGS. 2, 3, and 4Amay show a cross section of such a cylindrical, substantially cylindrical, and/or partially cylindrical formed thrust reverser cascade304and/or the linear thrust reverser cascade210. As the raised portion of the formed thrust reverser cascade304is farther from such a centerline than the corresponding portion of the linear thrust reverser cascade210, the surface area and hence, the cascade exit area, of the formed thrust reverser cascade304may be greater than the cascade exit area of the linear thrust reverser cascade210.

A greater cascade exit area may allow for a higher massflow of air through the thrust reverser cascade. A higher massflow of air may, accordingly, allow for increased thrust reversing capabilities. Additionally or alternatively, a greater cascade exit area may allow for a smaller (e.g., shorter) nacelle. E.g., a formed thrust reverser cascade may be shorter than a linear thrust reverser cascade of the same massflow. As such, a nacelle using a formed thrust reverser cascade may be a shorter length and/or smaller diameter than a nacelle with a linear thrust reverser cascade. Such a smaller nacelle may allow for lower drag, lower weight, or higher efficiencies in other manners.

FIG. 4Aillustrates a side view of a formed thrust reverser cascade in accordance with the disclosure.FIG. 4Amay illustrate a cross section of the formed thrust reverser cascade. The formed thrust reverser cascade304inFIG. 4Amay include a bullnose coupling portion412A, a first portion412B, a second portion412C, and a third portion412D. One, some, or all of the portions412A-D may include openings that allow air to flow through. Though the portions412A-D of the formed thrust reverser cascade304may be distinct portions (e.g., may include sharp bends between portions), other examples may include portions that include smoother transitions (e.g., radius'd transitions) between the portions or may include portions that constantly transition to other geometries (e.g., the formed thrust reverser or a portion thereof may be one or multiple continuous radius). Other examples of the formed thrust reverser cascade may omit certain portions of the formed thrust reverser cascade304illustrated inFIG. 4Aand/or may include other portions not described inFIG. 4A.

The bullnose coupling portion412A be configured to couple to the bullnose206. The bullnose coupling portion412A may also be parallel or substantially parallel (e.g., +/−15 degrees from parallel) with the bullnose206. Certain examples of the formed thrust reverser cascade304may not include the bullnose coupling portion412A and may, instead, be configured to couple to the bullnose206via the first portion412B.

The first portion412B may be disposed at a first angle to the bullnose coupling portion412A and/or a portion of the nacelle102, such as the bullnose206, that the formed thrust reverser cascade304may be configured to couple to. The second portion412C may be disposed at a second angle to, at least, the first portion412B. Accordingly, the second portion412C may, additionally, be disposed of at an angle to the bullnose coupling portion412A and/or a portion of the nacelle102.

The first portion412B may, in certain examples, be a portion of the formed thrust reverser cascade304that raises the second portion412C or another portion of the formed thrust reverser cascade304towards a portion of the aircraft propulsor100such as the translating sleeve124. As such, in certain examples, the second portion412C may be configured to be, for example, within less than an inch, within less than five inches, within less than ten inches, within less than two feet, or within two feet or more of the thrust reverser door124. At least a part of the second and/or third portions412B and/or412C may be farther from the centerline of the core engine208than the bullnose coupling portion412A and/or the bullnose206(or another portion of the aircraft nacelle102).

The third portion412D may be configured to couple to the cascade support ring208or another portion of the aircraft propulsor100. The third portion412D may include features (e.g., one or more forms, folds, bends, chamfers, and/or other features) allowing the formed thrust reverser cascade304to couple to the cascade support ring208. As such, the formed thrust reverser cascade304may be retrofitted to existing aircraft propulsors that utilize linear or other thrust reverser cascades.

FIG. 4Billustrates a perspective view of a formed thrust reverser cascade in accordance with examples of the disclosure.FIG. 4Bmay illustrate a perspective view of the formed thrust reverser cascade304described inFIG. 4A. The formed thrust reverser cascade304includes eggcrate shaped openings that allow for airflow through the openings, but other examples may include strake, gill, or other shaped openings. The openings may be defined, at least in part, by cascade vanes configured to direct air such as formed thrust reverser cascade vanes420A-C, as well as other cascade vanes. Additionally, the cascade vanes may be coupled to support structures, such as support structures422A-C, that connect a plurality of the formed thrust reverser cascade vanes. The support structures422A-C, in certain examples, may also condition airflow flowing through the formed thrust reverser cascade304. In certain examples, the cascade vanes may be arranged in substantially the width-wise direction while the support structures may be arranged in substantially the length-wise direction, though other examples may arrange the cascade vanes and/or the support structures in other directions.

InFIG. 4B, the formed thrust reverser cascade304may include a curved radii to allow the formed thrust reverser cascade304to be mounted on the nacelle102. As the nacelle102may be curved, the formed thrust reverser cascade304may include a curvature that matches or substantially matches a portion of the nacelle102. For example, the formed thrust reverser cascade304may be curved to match or substantially match the curvature of the bullnose206. As such, the width direction and/or other direction of the of the formed thrust reverser cascade304may be curved to allow the formed thrust reverser cascade304to be disposed circumferentially around the core engine248.

Certain examples of the aircraft propulsor100may include formed thrust reverser cascades that are disposed circumferentially around a portion or around the entire perimeter of the core engine248.FIG. 5illustrates a front cutaway view of an aircraft propulsor with a thrust reverser cascade disposed circumferentially around the core engine in accordance with examples of the disclosure.

The aircraft propulsor100ofFIG. 5includes the core engine248, the formed thrust reverser cascade304, and the bypass flow path256. As shown inFIG. 5, the formed thrust reverser cascade304may be disposed circumferentially around the entire perimeter of the core engine248. The bypass flow path256may be disposed of between the core engine248and the formed thrust reverser cascade304. Airflow within the bypass flow path256, energized by the core engine248, may be redirected through the formed thrust reverser304to provide reverse thrust for the aircraft propulsor100.

FIG. 6illustrates a side cutaway view of a linear thrust reverser cascade compared to a formed thrust reverser cascade in accordance with examples of the disclosure. The formed thrust reverser cascade304includes a plurality of formed thrust reverser cascade vanes, including formed thrust reverser cascade vanes420A-C.

The formed thrust reverser cascade vanes420A-C, as well as other formed thrust reverser cascade vanes, may include radii, chamfers, vanes, and other angled features that may redirect air. Such features may allow for increased thrust reversing capabilities for the aircraft propulsor100by, for example, changing the direction of airflow to provide greater reverse thrust. In certain examples, the formed thrust reverser cascade vanes in different portions of the formed thrust reverser cascade304may be different geometries to condition the airflow to more optimally provide reverse thrust. Additionally, in certain examples, such as in situations where the formed thrust reverser cascade is retrofitted onto existing propulsors, the geometries of the formed thrust reverser cascade vanes may be shaped so that air exiting from the formed thrust reverser cascade vanes may flow in the same direction or substantially the same direction as that of the air exiting from the vanes of the linear thrust reverser cascade.

During computer simulations, the formed thrust reverser cascade has shown increased performance as compared to a linear thrust reverser cascade. In certain examples, a linear thrust reverser cascade may be disposed of at a distance of approximately 75 inches from a centerline of a core engine. A formed thrust reverser cascade may, due to the raised portion, be disposed of at an average distance of approximately 80 inches from the centerline of the core engine while being the same length as the linear thrust reverser cascade. Such a formed thrust reverser may allow for an approximately 3-4% higher airflow rate as compared to the linear thrust reverser cascade. As such, the formed thrust reverser cascade may allow for higher reverse thrust.

Additionally or alternatively, the formed thrust reverser cascade may allow for a more compact aircraft propulsor. Returning to the example above, the formed thrust reverser cascade disposed of at an average distance of approximately 80 inches from the centerline of the core engine may be 4% shorter while maintaining the same airflow rate as the linear thrust reverser cascade disposed of at a distance of approximately 75 inches from the centerline of the core engine. As such, the formed thrust reverser cascade may be used to additionally or alternatively decrease the size of the aircraft propulsor.