Acoustic panel for thrust reversers

An acoustic panel includes a base, a cantilevered portion, a gap, and a support member. The base has a surface defining a plurality of cavities configured to attenuate noise from an engine. The cantilevered portion extends from the base and is configured to be removably coupled with a portion of a transcowl. The gap is defined by the base and the cantilevered portion. The support member is coupled to the cantilevered portion and the base, and the supporting member is configured to support the cantilevered portion.

FIELD OF THE DISCLOSURE

The present disclosure is generally related to acoustic panels including a cantilevered doubler.

BACKGROUND

Airplanes with jet engines are often equipped with thrust reversers that increase drag on the airplane during landings, thereby reducing the speed of the aircraft. A thrust reverser increases drag by effectively reversing the flow of bypass or exhaust gases through the jet engine. In one type of thrust reverser, referred to as a cascade-type, a transcowl on the jet engine nacelle translates rearwardly to redirect the airflow forwardly and thereby produce reverse thrust.

The transcowl is coupled to an acoustic panel which reduces engine noise and provides aerodynamic surfaces on both sides (inside and outside surfaces) of the acoustic panel. The acoustic panel is a complex part because it has very high design requirements for noise reduction, aerodynamic drag, and structural support. The acoustic panel is coupled to the transcowl via fasteners that go through the entire thickness of the acoustic panel, fasteners that only attach to one facesheet of the acoustic panel, or adhesives. When fasteners are used, the area where the acoustic panel is coupled to transcowl may not be acoustically active and may be heavier because fasteners are used to join the two pieces. When adhesives are used, decoupling of the acoustic panel from the transcowl for maintenance and service of the jet engine or nacelle degrades performance and creates extra service time for repairing and rebonding or fasteners are used to recouple the acoustic panel to the transcowl. Additionally, removing and re-installing the above fasteners can degrade performance and creates extra service time. Thus, current acoustic panels may have significant acoustically inactive regions, leading to reduced acoustic performance, and/or are very expensive and time consuming to fabricate and maintain.

SUMMARY

In a particular implementation, an acoustic panel includes a base having a surface defining a plurality of cavities configured to attenuate noise from an engine. The acoustic panel also includes a cantilevered portion extending from the base and configured to be removably coupled with a portion of a transcowl. The acoustic panel includes a gap defined by the base and the cantilevered portion. The acoustic panel further includes a support member coupled to the cantilevered portion and coupled to the base, the support member configured to support the cantilevered portion.

In another particular implementation, a vehicle includes an engine, a cowl partially enclosing the engine, and a thrust reverser assembly. The thrust reverser assembly is coupled to the cowl. The thrust reverser assembly includes a transcowl and includes an acoustic panel configured to attenuate noise from the engine. The acoustic panel includes a base having a surface defining a plurality of cavities. The acoustic panel also includes a cantilevered portion extending from the base and configured to be removably coupled with a portion of the transcowl. The acoustic panel includes a gap defined by the base and the cantilevered portion. The acoustic panel further includes a support member coupled to the cantilevered portion and coupled to the base, the support member configured to support the cantilevered portion.

In a particular implementation, a method of manufacturing an acoustic panel includes applying a layer of composite material to a base, the base having a surface defining a plurality of cavities. The method also includes applying a layup support member to the layer of composite materials. The method further includes forming a cantilevered portion extending from the base. The layup support material is positioned between the base and the cantilevered portion. After forming, the cantilevered portion is configured to be coupled to and support another component, and a portion of a surface of the cantilevered portion is an aerodynamic surface.

By using an acoustic panel with a cantilevered portion, the cantilevered portion can be attached to another component and the acoustic panel has an increased acoustically active area, a potential for a lower weight configuration, and offers easier maintenance and servicing of the acoustic panels. Additionally, maintaining and servicing the acoustic panel does not degrade performance like compared to conventional configurations. Accordingly, engine noise is decreased, which leads to less noise pollution and enables an aircraft to operate during restricted noise times.

DETAILED DESCRIPTION

The disclosed embodiments provide a lighter and higher performing acoustic panel for use in thrust reversers to make the thrust reversers easier to assemble and disassemble. A method of manufacturing the acoustic panel is also disclosed. Thrust reversers are commonly included in or form a portion of a nacelle of an aircraft. In the context of a nacelle of an aircraft, acoustic performance, manufacturing costs, and repairability are major factors. Acoustic performance is primarily affected by an amount of surface area that is acoustically active, i.e., a larger acoustically active area reduces engine noise output. For example, the acoustically active area vibrates to dissipate or dampen noise generated by the engine. However, using fasteners (e.g., removable fasteners) reduces the acoustically active area. Special permanent fasteners (e.g., blind permanent fasteners that only attach to one facesheet of the acoustic panel and that penetrate the acoustically active area) can be used to limit the reduction in acoustically active area, but upon servicing the part or area, the benefit is lost.

Nacelle components are high value components and are expensive to produce because their structural and functional requirements (e.g., aerodynamic and acoustical properties). To meet such structural and functional requirements, the manufacturing of nacelle components includes multiple tools, machines, and processes. In particular, a thrust reverser outer acoustic panel has aerodynamic requirements on both the outer and inner surfaces, and is the most expensive component of the thrust reverser. In-service repairs are common as nacelles are exposed to both man-made and natural damage. The close proximity of these structures to the ground and regular engine maintenance requirements makes them very susceptible to damage from tool drop, handling, and support vehicles. Nacelles are also commonly exposed to natural damage such as lightning strikes and hail strikes. It is common for a translating sleeve (e.g., a transcowl) of the thrust reverser, the most prone to damage due to exposed surfaces, to be disassembled for these types of repair. Unfortunately because of the high level of integration and permanent attachment schemes, disassembly for repair operations can be expensive, be time consuming, increase drag, and reduce acoustic performance.

The acoustic panels described herein include a cantilevered portion that extends outwards from a base of the acoustic panel. The cantilevered portion is supported by a support member and is configured to attach to another component, such as the transcowl. The cantilevered portion simplifies bond panel manufacturing operations, reduces weight, increases the acoustically active area, and makes the translating sleeve more repairable. Cantilevering an attachment area (e.g., an attachment flange) over the base of the acoustic panel eliminates special through fasteners or special blind fasteners which typically extend through an attachment area of the base and require modifications to the base surrounding the attachment area. Accordingly, more standard, less expensive bolts can attach the transcowl to this attachment area using a nut plate and bolt. Furthermore, disassembly of the transcowl from the cantilevered portion does not result in an acoustically active area loss and can be done with less specialized tools as compared to conventional configurations.

FIG. 1illustrates a block diagram of an example of an aircraft100that includes a nacelle102and a propulsor112. The nacelle102is configured to house the propulsor112and to be coupled to the aircraft100. The propulsor112is housed within the nacelle102and is configured to generate thrust. The propulsor112includes or corresponds to a jet engine or another type of propulsor.

The nacelle102includes a cowl114and a thrust reverser assembly116(referred to herein as a thrust reverser116). The nacelle102is coupled to the aircraft100via a strut or a pylon. The nacelle102can be connected to a wing of the aircraft100, a fuselage of the aircraft100, or an empennage (tail section) of the aircraft100.

The cowl114is configured to house (partially encase or enclose) the propulsor112and includes multiple sections or pieces. As illustrated inFIG. 1, the cowl114includes an inlet cowl122. The cowl114is configured to reduce propulsor noise, to protect the propulsor112, and to direct airflow to the propulsor112. In some implementations, the cowl114includes a second portion (e.g., a fan cowl212ofFIG. 2). The second portion (e.g., the fan cowl212) may form an intermediary portion of the nacelle102and may be positioned between the inlet cowl122and a transcowl124.

The thrust reverser116is configured to generate thrust. For example, the thrust reverser116is configured to generate forward thrust in a first configuration and is configured to generate reverse thrust in a second configuration. The reverse thrust includes thrust in a direction opposite the propulsor112, thrust in a direction that opposes a direction of travel of the aircraft100, and/or thrust that reduces the forward thrust (e.g., thrust that propels the aircraft100in a forward direction). The thrust reverser116includes or corresponds to a translating thrust reverser, a cascade thrust reverser, a cold stream thrust reverser, a clamshell thrust reverser, or a combination thereof.

In a translating thrust reverser116, the thrust reverser116vents bypass airflow from the propulsor112out of an opening in the nacelle102. The opening in the nacelle102is created by the transcowl124translating rearwards or aft from the cowl114(e.g., the inlet cowl122and/or the fan cowl212ofFIG. 2), as described further with respect toFIGS. 2-4.

The thrust reverser116is coupled (e.g., moveably coupled) to the cowl114and includes the transcowl124and an acoustic panel132configured to reduce or attenuate propulsor noise. The acoustic panel132also directs airflow within the nacelle102and forms an outer portion of the nacelle102. Thus, the acoustic panel132has aerodynamic surfaces. The aerodynamic surfaces are configured to provide low drag. For example, the surfaces (or portions of the surfaces) of the acoustic panel132are machined to have a contour that reduces drag and have a composition (e.g., a surface material and/or smoothness) that reduces drag.

The acoustic panel132includes a base142, a cantilevered portion144, and a support member146. The base142, the cantilevered portion144, and the support member146are joined (e.g., fixedly coupled or fixedly adhered) to form a monolithic piece. Fabrication of the acoustic panel132is further described with reference toFIGS. 9-13 and 18. The acoustic panel132(i.e., the cantilevered portion144thereof) is coupled to a portion of the transcowl124. In some implementations, the acoustic panel132forms and/or defines an exterior portion or surface of the nacelle102. Although one acoustic panel132is illustrated inFIG. 1, the nacelle102(e.g., the cowl114thereof) may include additional acoustic panels132.

The base142(e.g., a base member) includes a plurality of cavities configured to reduce or attenuate propulsor noise. For example, the base142includes a plurality of hexagonal shaped (e.g., honeycomb shaped) cavities that dampen or absorb sound waves and block sound waves generated by the propulsor112. The hexagonal shaped cavities also provide a relatively high degree of strength per weight and are repeatable without overlaps or gaps (i.e., hexagonal shaped cavities are capable of being efficiently tessellated).

The cantilevered portion144is configured to couple to a portion of the transcowl124. For example, in a cascade-type thrust reverser, the cantilevered portion144is coupled to the transcowl124via fasteners, as described further with reference toFIG. 17. The cantilevered portion144may include or correspond to a doubler (or a portion thereof), as described further with reference toFIG. 8. A doubler is a laminated support member and is often used as a support for a skin or an external portion of the aircraft100. As compared to conventional acoustic panels which do not include a cantilevered portion and couple to an acoustically active area to the transcowl124, coupling the cantilevered portion144to the transcowl124increases the acoustically active area of the acoustic panel132, reduces a weight of the acoustic panel132, and facilitates maintenance and servicing without performance losses.

The support member146is configured to support the cantilevered portion144and to absorb loads during operation of the aircraft100. The support member146may include or correspond to a noodle814or a molded insert1512, as described with reference toFIGS. 8 and 15.

In other implementations, the propulsor112is included in a fuselage or empennage of the aircraft100, such as in a tri-jet aircraft. In such implementations the cantilevered portion144is coupled to a portion of the fuselage or empennage of the aircraft instead of being coupled to a portion of the transcowl124.

Although the acoustic panel132has been described as an acoustic panel (e.g., an outer acoustic panel or wall) of a thrust reverser116, the acoustic panel132may couple to other components. The aerodynamic surfaces of the acoustic panel132provide low drag and the cantilevered portion144allows the acoustic panel132to be coupled with other components and provide a higher quality aerodynamic surface. For example, the acoustic panel132may be coupled to flight control surfaces and components thereof.

The acoustic panel132may be manufactured by exemplary methods of manufacturing described with reference toFIGS. 9-13 and 18. Additionally, the methods of manufacturing the acoustic panel132can be applied to manufacturing other components to increase an active area of a base member thereof, to join two components to form an aerodynamic surface, or to couple a second component to a first component via a cantilevered portion144rather than via a base142of the first component, such as for design constraints (e.g., repairability, manufacturing time, costs, etc.).

Operation of an exemplary thrust reverser116including the acoustic panel132is described with reference toFIGS. 2-4. Referring toFIGS. 2-4, an example of a cascade-type thrust reverser assembly and operation thereof is depicted by diagrams200-400.FIG. 2is a diagram200that illustrates a side view of the nacelle102of the aircraft100depicting the transcowl124having shifted rearwardly (as indicated by the arrow) to expose the (cascade-type) thrust reverser116.FIG. 3is a diagram300that illustrates a perspective view of the nacelle102and the thrust reverser116shown inFIG. 2.FIG. 4is a diagram400that illustrates a cross-section view of a portion of the nacelle102shown inFIGS. 2 and 3, depicting airflow through the thrust reverser116.

As illustrated inFIG. 2, the cascade-type thrust reverser116includes a plurality of circumferentially arranged, thrust reversing cascade grid panels202, sometimes referred to as cascade baskets. During normal flying operations, the transcowl124is in a closed, forward position, joining the transcowl124with the cowl114(e.g., the inlet cowl122and/or the fan cowl212), and thereby covering the cascade grid panels202.

During landing, the transcowl124is moved from its closed position to its open, rearwardly extended position (as shown inFIGS. 2-4) by actuator rods410ofFIG. 4. Opening the transcowl124exposes the cascade grid panels202to the surrounding environment. When the transcowl124is in the open position, the thrust reverser116is activated by deploying circumferentially located blocker doors408ofFIG. 4. Deploying the blocker doors408prevents bypass exhaust from flowing out of a nozzle312ofFIG. 3and forces the bypass exhaust through the cascade grid panels202, as shown by the arrows412inFIG. 4. Each of the cascade grid panels202includes a plurality of axially extending strongbacks (not shown), a plurality of vanes406extending between the strongbacks, and fore and aft mounting flanges402,404respectively. The cascade grid panels202direct the flow of the exhaust forward, and optionally radially outward, producing a reversal in the direction of the exhaust flow. This reversal of the bypass exhaust flow results in a reversal of thrust that assists in slowing down the aircraft100.

As illustrated inFIGS. 3 and 4, the acoustic panel132is coupled to the transcowl124and forms an exterior portion of the nacelle102. To illustrate, an exterior surface (i.e., an aerodynamic surface) of the acoustic panel132corresponds to or forms a portion of an exterior portion of the nacelle102(e.g., forms a portion of the transcowl124).FIG. 4also illustrates that an interior surface of the acoustic panel132defines the nozzle312and is a second aerodynamic surface which directs the bypass exhaust when the transcowl124is in the forward or closed position. The acoustic panel132(e.g., the plurality of cavities thereof) attenuates noise produced by the propulsor112.

FIG. 5is a diagram500that illustrates a cross-section view of an example of the acoustic panel132ofFIG. 1. Because the acoustic panel132is annular shaped, the cross-section illustrated inFIG. 5includes an upper portion512(e.g., an upper-cross section) and a lower portion514(e.g., a lower cross-section). The acoustic panel132ofFIG. 5has a similar shape to the shape of the acoustic panel132ofFIGS. 3 and 4.

The acoustic panel132includes aerodynamic surfaces522,524. A first aerodynamic surface522includes or corresponds to an exterior or external aerodynamic surface, i.e., an aerodynamic surface for exterior airflow of the nacelle102. A second aerodynamic surface524includes or corresponds to an interior aerodynamic surface, i.e., an aerodynamic surface for fan duct bypass air flowing out of the nozzle312ofFIG. 3(when the blocker doors408ofFIG. 4are stowed). As illustrated inFIG. 5, the upper portion512includes aerodynamic surfaces522A and524A and the lower portion514includes aerodynamic surfaces522B and524B.

The upper portion512illustrates two areas of the acoustic panel132in dashed boxes, a fore portion532and an aft portion534. The fore portion532includes a first machined transition area542. In the machined transition areas, a surface of the acoustic panel132may be machined, processed, or finished to meet design requirements regarding a thickness of the acoustic panel132. The aft portion534includes that cantilevered portion144and the support member146. A second machined transition area544begins near the aft portion534(e.g., at the cantilevered portion) and extends rearward or aftward. The second machined transition area544may extend to a rear or aft end of the acoustic panel132in some implementations.

FIG. 6illustrates a side view of the acoustic panel132ofFIG. 5. InFIG. 6, the machined transition areas542,544are shown in dashed boxes612. As illustrated inFIG. 6, the cross-section of the acoustic panel132is not the same over the entire span of the acoustic panel132, i.e., the acoustic panel132may be non-symmetrical with respect to a particular axis. Additionally, as the nacelle102may include multiple acoustic panels132, each acoustic panel132may have a different shape than another acoustic panel132. As compared to conventional acoustic panels132which are joined at a base member, the acoustic panel132has a reduction in machined transition areas542,544(e.g., machined transitions surfaces). For example, in conventional acoustic panels132which are joined at a base member, the entire acoustic panel132has machined surfaces, which increases fabrication time and costs.

FIGS. 7A-7Cillustrate an example of the acoustic panel132and the base142thereof.FIG. 7Ais a diagram that illustrates a cross-section view of the fore portion532of the acoustic panel132ofFIG. 3. InFIG. 7A, the base142of the acoustic panel132has a first surface712and a second surface714. The base142includes a plurality of cavities722, as illustrated inFIG. 7B, positioned (e.g., sandwiched) between two facesheets742,744, as illustrated inFIG. 7C.

FIG. 7Bdepicts surfaces732,734of the base142defining the plurality of cavities722. The plurality of cavities722of the base142have a hexagonal shape (e.g., a honeycomb shape), and the base142includes or corresponds to a “honeycomb structure” with the plurality of cavities722forming a “core” of the honeycomb structure. In other implementations, one or more of the plurality of cavities722have other shapes, such as a circular shape, a rectangular shape, a square shape, a pentagonal shape, an octagonal shape, another shape which may be tessellated, or a combination thereof. The plurality of cavities722are illustrated inFIG. 7Bas extending through the base142of the acoustic panel132, i.e., the plurality of cavities722correspond to through holes and are defined by both surfaces732,734. In other implementations, the plurality of cavities722do not extend through the acoustic panel132. In a particular implementation, each of the surfaces732,734defines a corresponding plurality of cavities722.

The acoustic panel132(e.g., portions thereof) includes facesheets742,744coupled to the surfaces732,734that define the plurality of cavities722of the base142, as illustrated inFIG. 7C. In a particular implementation, the facesheets742,744include composite material, as further described with reference toFIG. 8. The facesheets742,744may include or correspond to a skin of the acoustic panel132(and the nacelle102) and include the surfaces712,714.

FIG. 8illustrates a cross-section view of an example of the aft portion534of the acoustic panel132ofFIG. 3. The aft portion534of the acoustic panel132includes the base142, the cantilevered portion144, and the support member146.

In the example illustrated inFIG. 8, the base142includes a top surface (corresponding to the first surface712ofFIG. 7) and a bottom surface (corresponding to the second surface714ofFIG. 7). A first layer of composite material812is coupled to at least a portion of the top surface of the base142. In some implementations, the first layer of composite material812is configured to adhere or secure a doubler816to the base142, as described with reference toFIGS. 9-13.

The doubler816is coupled to the base142and extends from the base142defining a gap820. As illustrated inFIG. 8, the doubler816is in contact with the first layer of composite material812and is in contact with the base142. In other implementations, the doubler816is in contact with the first layer of composite material812and the first layer of composite material812is in contact with the first surface712(e.g., the top surface) of the base142.

The doubler816includes a proximal end832(proximal portion) and a distal end834(distal portion). The proximal end832is fixed or anchored to the base142, such as a fixed or anchored end. The distal end834is free or floating relative to the base142, such as a free end. A portion of the doubler816near and including the distal end834includes or corresponds to the cantilevered portion144ofFIG. 1, as depicted inFIG. 8.

The cantilevered portion144of the doubler816is configured to be coupled to the transcowl124ofFIG. 1(or another component). For example, the cantilevered portion144is removably coupled with the transcowl124by fasteners (not shown inFIG. 8), as illustrated and described with reference toFIG. 17.

The doubler816includes composite material, such as carbon fiber reinforced polymers (CFRP). In some implementations, the doubler816is pre-formed (e.g., pre-cured) prior to attachment to the base142and assembly/formation of the acoustic panel132, as described with reference toFIGS. 9-13 and 18. In other implementations, the doubler816is formed by disposing composite materials (e.g., uncured composite materials) onto the base142(or layers and components thereof) and curing the composite materials to form the doubler816. A gap820is formed between and defined by the cantilevered portion144of the doubler816and the base142.

A support member146is positioned between the doubler816and the base142. As illustrated inFIG. 8, the support member146is a noodle814and is positioned between and in contact with the first layer of composite material812and the doubler816. The noodle814is configured to support the doubler816. For example, the noodle814supports the doubler816during operation and when coupled to the transcowl124ofFIG. 1. A separate component or material (e.g., a layup support member1112of FIG.11) may be used to support the doubler816during attachment of the doubler816to the base142or during formation of the doubler816, as described with reference toFIG. 12. In some implementations, the noodle814includes a material having similar properties to the surrounding materials. For example, the noodle814includes a material that has similar elasticity and strength to the composite materials of the doubler816and the layers of composite material812,818,822.

In the example illustrated inFIG. 8, the acoustic panel132further includes a second layer of composite material818coupled to the first layer of composite material812, the support member146, and the doubler816. The second layer of composite material818is configured to support the cantilevered portion144during operation and to couple (e.g., secure) the support member146to the first layer of composite material812and the base142.

In some implementations, the acoustic panel132includes an adhesive. For example, the acoustic panel132may include a layer of the adhesive positioned between the second layer of composite material818and each of the first layer of composite material812, the noodle814, and the doubler816. The adhesive is configured to couple (e.g. fixedly couple or adhere) the second layer of composite material818to each of the first layer of composite material812, the noodle814, and the doubler816. In some implementations, the adhesive is an epoxy-type adhesive. In other implementations, other type of adhesives can be used which can join composite materials.

A third layer of composite material822is coupled to the second surface714(e.g., the bottom surface) of the base142. The composite material of the layers of composite material812,818,822may include or correspond to uncured composite material. In a particular implementation, the composite material of the layers of composite material812,818,822include uncured (e.g., “green”) CFRP plies. The composite material of the layers of composite material812,818,822may include the same type of composite material or different types of composite material. The layers of composite material812,822may include or correspond to facesheets, such as the facesheets742,744ofFIG. 7.

As illustrated inFIG. 8, the doubler816is tapered862. To illustrated, the distal end834of the doubler816is thicker than the proximal end832of the doubler816.FIG. 8illustrates the aerodynamic surface522and524ofFIG. 5. A portion of the cantilevered portion144forms a portion of the first aerodynamic surface522of the acoustic panel132. For example, a portion of the surface of cantilevered portion144that is aftward or rearward of the transcowl124and extends in towards the aft of the acoustic panel132forms a portion of the first aerodynamic surface522of the acoustic panel132.

FIG. 9is a diagram900illustrating a first manufacturing stage of a process of manufacturing an acoustic panel132according to a particular aspect of the disclosure. The first manufacturing stage, as illustrated inFIG. 9, includes placing the base142on a tool902and depositing the first layer of composite material812on at least a portion of the base142. As illustrated inFIG. 9, the first layer of composite material812has a tapered section912near an aft end of the first layer of composite material812. In other implementations, the tapered section912may extend further forward or the entire layer of the composite material812may be tapered. Alternatively, the layer of composite material812may extend to the aft edge of the base142. The first layer of composite material812may be applied or deposited by hand or by machine. In a particular implementation, the composite material of the first layer of composite material812is uncured (e.g., “green”) CFRP plies.

The tool902is configured to support components of the acoustic panel132during layup and curing of the components of the acoustic panel132. The tool902includes a geometry or shape that is configured to support formation of the acoustic panel132or components thereof. Although a single tool902is illustrated inFIGS. 9-13, multiple tools902may be used in other implementations.

In some implementations, the third layer of composite material822is deposited prior to depositing the first layer of composite material812, as illustrated inFIG. 9. In other implementations, the third layer of composite material822is deposited after depositing the first layer of composite material812. Applying the third layer of composite material822to the base142may be done similar to applying the first layer of composite material812. For example, the third layer of composite material822is deposited on the tool902and the base142is applied on top of the third layer of composite material822or the base142is placed on the tool902or another tool and the third layer of composite material822is applied to the base142by hand or by machine. In a particular implementation, the first manufacturing stage further includes a curing step to cure the first layer of composite material812, the third layer of composite material822, or both. Alternatively, the first layer of composite material812, the third layer of composite material822, or both, can be cured during a later manufacturing stage. Additionally, the third layer of composite material822can be cured at an earlier manufacturing stage.

FIG. 10is a diagram1000illustrating a second manufacturing stage of a process of manufacturing the acoustic panel132according to a particular aspect of the disclosure. The second manufacturing stage illustrated inFIG. 10may be subsequent to the first manufacturing stage ofFIG. 9.

In the second manufacturing stage ofFIG. 10, support material1012(which is cured to form the support member146ofFIG. 1) is deposited or applied to the base142. As illustrated inFIG. 10, the support material1012is deposited on and is in contact with the first layer of composite material812. The support material1012may include or correspond to composite materials, such as uncured CFRP, or another material which has material properties similar to the composite materials. Alternatively, the support member146is placed or positioned on the base142. In such implementations, the support member146is pre-cured, pre-formed, or machined prior to placement on the base142. In a particular implementation, the second manufacturing stage further includes a curing step to cure the support material1012, the first layer of composite material812, the third layer of composite material822, or a combination thereof. Alternatively, the support material1012, the first layer of composite material812, the third layer of composite material822, or a combination thereof, can be cured during a later manufacturing stage.

FIG. 11is a diagram1100illustrating a third manufacturing stage of a process of manufacturing the acoustic panel132according to a particular aspect of the disclosure. The third manufacturing stage illustrated inFIG. 11may be subsequent to the second manufacturing stage ofFIG. 10.

In the third manufacturing stage ofFIG. 11, a layup support member1112and the second layer of composite material818are placed or positioned on the base142. For example, the second layer of composite material818is applied to the layup support member1112and the joined layup support member1112and second layer of composite material818is positioned on the base142(e.g., positioned in the gap820illustrated inFIG. 8). As illustrated inFIG. 11, the second layer of composite material818is in contact with the layup support member1112, the first layer of composite material812, and the support member146or the support material1012. The layup support member1112may include or correspond to a rubber material, as an illustrative, non-limiting example. The layup support member1112can include or correspond to other materials that can support composite materials under heat and/vacuum pressure without deforming outside of design tolerances. The layup support member1112is configured to support the second layer of composite material818and the cantilevered portion144prior to coupling the cantilevered portion to the base142, as described with reference toFIG. 12.

In some implementations, the third manufacturing stage further includes applying the adhesive to at least a portion of an outside surface of the second layer of composite material818. The adhesive may be applied to the second layer of composite material818before or after deposition of the second layer of composite material818onto the layup support member1112. Additionally or alternatively, the adhesive is applied to first layer of composite material812, the support material1012, the support member146, or another component that the second layer of composite material is coupled to. In a particular implementation, the third manufacturing stage further includes curing the second layer of composite material818, the support material1012, the first layer of composite material812, the third layer of composite material822, the adhesive, or a combination thereof. Alternatively, the second layer of composite material818, the support material1012, the first layer of composite material812, the third layer of composite material822, the adhesive, or a combination thereof, can be cured during a later manufacturing stage.

FIG. 12is a diagram1200illustrating a fourth manufacturing stage of a process of manufacturing the acoustic panel132according to a particular aspect of the disclosure. The fourth manufacturing stage illustrated inFIG. 12may be subsequent to the third manufacturing stage ofFIG. 11.

In the fourth manufacturing stage ofFIG. 12, a pre-cured (pre-formed) composite component1216(e.g., the doubler816) is placed on the base142, the support member146, and the layup support member1112to form the cantilevered portion144and the gap820. The components are then cured to secure the pre-cured (pre-formed) composite component1216to the base142to form the doubler816and the cantilevered portion144. For example, the components are cured in an autoclave or formed by a draping process (e.g., hot draping or vacuum deposition).

In other implementations, uncured composite material (referred to as second composite material) is deposited on the second layer of composite material818, the support member146(e.g., the support material1012), and/or the layup support member1112and is cured to form the cantilevered portion144. To illustrate, second composite material is laid up on one or more of the support member146(e.g., the support material1012) and the second layer of composite material818(which is supported by the layup support member1112), and a rigid tool (e.g., a caul plate) is placed on top of the second composite material. Heat and pressure are applied to the caul plate during a curing process, and the caul plate transfers the heat and pressure to cure the second composite material. Additionally, curing the second composite material using the caul plate can be used to cure one or more layers of composite material812,818,822, the support material1012, or a combination thereof. In some such implementations, the layup support member1112, the second layer of composite materials818, or both, may extend to or past the distal portion of the cantilevered portion144, as illustrated inFIG. 12.

In some implementations, the second layer of composite material818is formed such that the second layer of composite material818extends to the distal end834of the cantilevered portion144and the pre-cured (pre-formed) composite component1216and the second layer of composite material818is later reduced (e.g., by cutting or machining) such that the second layer of composite material818does not extend to the distal end834(similar to the second layer of composite material818ofFIG. 8). In other implementations, the second layer of composite material818is formed such that it does not extend to distal end834of the cantilevered portion144and the pre-cured (pre-formed) composite component1216.

FIG. 13is a diagram1300illustrating a fifth manufacturing stage of a process of manufacturing the acoustic panel132according to a particular aspect of the disclosure. The fifth manufacturing stage illustrated inFIG. 13may be subsequent to the fourth manufacturing stage ofFIG. 12.

In the fifth manufacturing stage ofFIG. 13, after acoustic panel132is joined by curing, the layup support member1112is removed and the gap820is formed. In some implementations, the acoustic panel132is machined after curing. In some implementations, the third layer of composite material822is deposited after the layup support member1112is removed. In other implementations, the third layer of composite material822is deposited prior to the layup support member1112being removed. For example, the third layer of composite material822may be deposited on the base142prior to the first manufacturing stage or prior to the fifth manufacturing stage.

Additionally or alternatively, fasteners or fastener supports are placed on the cantilevered portion144, as described further with reference toFIG. 17. By coupling the cantilevered portion144to another component, as opposed to coupling the other component to the base142, an acoustically active area of the base142is increased. To illustrate, the base142has an additional acoustically active area indicated by an area within a dashed box1302ofFIG. 13as compared to acoustic panels which couple the acoustic panel132to another component by using fasteners in the area within the dashed box1302. Special blind permanent fasteners can limit acoustic area losses initially, but lose that performance if the panels are separated for maintenance and servicing.

FIG. 14is a diagram1400that illustrates a cross-section view of another example of the aft portion534of the acoustic panel132ofFIG. 3. As illustrated inFIG. 14, the doubler816and the cantilevered portion144include a joggle1412(e.g., a notch or faired in portion). The joggle1412provides a recessed portion1414(recessed surface) for coupling with another component to form an aerodynamic surface. The recessed portion1414provides for a smoother transition between an exterior surface of the cantilevered portion144and an exterior surface of the other component to which the cantilevered portion144is attached. In a particular implementation no aerodynamic seal is used between the other component and the acoustic panel132or a size of an aerodynamic seal between the other component and the acoustic panel132is reduced.

FIG. 15is a diagram1500that illustrates a cross-section view of another example of the aft portion534of the acoustic panel132ofFIG. 3. As compared to the example acoustic panels132ofFIGS. 13 and 14which have a noodle814for the support member146, the acoustic panel132ofFIG. 15has a molded insert1512for the support member146. In a particular implementation, the molded insert1512includes or corresponds to a thermoplastic material or a thermoset polymer material.

As illustrated inFIG. 15, the molded insert1512is larger than the noodle814and extends further towards the distal end834than the noodle814ofFIGS. 8 and 14. Although the molded insert1512extends to the distal end834in the example illustrated inFIG. 15, in other implementations the molded insert1512does not extend all the way to the distal end834.

As illustrated inFIG. 15, the second layer of composite material818is larger (longer) and extends further towards the distal end834than the second layer of composite material818ofFIG. 8. Although the second layer of composite material818extends to the distal end834in the example illustrated inFIG. 15, in other implementations, the second layer of composite material818does not extend all the way to the distal end834.

As illustrated inFIG. 15, the pre-cured composite component1216(e.g., the doubler816) is thinner than the pre-cured composite component1216(e.g., the doubler816) ofFIGS. 13 and 14. The pre-cured composite component1216(e.g., the doubler816) ofFIG. 15has a substantially constant cross-section and thickness (i.e., does not taper), as compared to the tapered pre-cured composite component1216(e.g., the doubler816) ofFIGS. 13 and 14.

FIG. 16is a diagram1600that illustrates a cross-section view of another example of the aft portion534of the acoustic panel132ofFIG. 3. Similar to the example acoustic panel132ofFIG. 15, the acoustic panel132ofFIG. 16has a molded insert1512for the support member146. As compared to the example acoustic panels132ofFIGS. 13 and 15, the cantilevered portion144of the acoustic panel132ofFIG. 16is joggled. To illustrate, the acoustic panel132includes a joggle1412and a recessed receiving portion1414, similar to the cantilevered portion144of the acoustic panel132ofFIG. 14.

As illustrated inFIG. 16, the second layer of composite material818is larger (longer) and extends further towards the distal end834than the second layer of composite material818ofFIG. 8. Although the second layer of composite material818extends to the distal end834in the example illustrated inFIG. 16, in other implementations, the second layer of composite material818does not extend all the way to the distal end834.

Similar to the pre-cured composite component1216(e.g., the doubler816) ofFIG. 15, the pre-cured composite component1216(e.g., the doubler816) ofFIG. 16has a substantially constant cross-section and thickness (i.e., does not taper). The acoustic panels132ofFIGS. 14-17may be manufactured similar to the acoustic panel132ofFIG. 8, e.g., by one of more of the manufacturing stages illustrated inFIGS. 9-13. In some implementations, the acoustic panels132ofFIGS. 14-16include the adhesive, as described with reference toFIGS. 8 and 11.

FIG. 17is a diagram1700that illustrates a cross-section view of an example coupling between the cantilevered portion144of the acoustic panel132ofFIG. 3and the transcowl124ofFIG. 1. InFIG. 17, two example couplings are illustrated using different types of fastener assemblies1702,1704. A first coupling includes a first fastener assembly1702extending through the transcowl124and the cantilevered portion144. As an illustrative, non-limiting example, the first fastener assembly1702includes a bolt1712and a nut1714. In a particular implementation, the bolt1712and the nut1714include or correspond to flush head bolt and nut or a double-flush head bolt and nut. In such implementations, a technician (or two technicians) may require access to both the top surface and bottom surface (e.g., access to the gap820) to fasten and unfasten (remove) the first fastener assembly1702.

A second coupling includes a second fastener assembly1704, such as a nut plate1724, rivets1726, and the bolt1712. In the second coupling, the bolt1712extends through the transcowl124and the cantilevered portion144. The nut plate1724is coupled to the cantilevered portion144by fasteners (e.g., the rivets1726, screws, etc.) or adhesive or is fixed to the cantilevered portion144during curing. In such implementations, the transcowl124can be decoupled from the acoustic panel132without access to the gap820.

The transcowl124may be coupled to the cantilevered portion144using one or more first fastener assemblies1702, one or more second fastener assemblies1704, or a combination thereof. Although the first fastener assembly1702is illustrated as extending through the middle of the cantilevered portion144(e.g., the doubler816), the first fastener assembly1702(e.g., the bolt1712thereof) may extend through the proximal portion of the cantilevered portion (e.g., extend through the doubler816and the second layer of composite material818).

In the implementation illustrated inFIG. 17, the cantilevered portion144includes the joggle1412and the transcowl124has a shape complementary to a shape of the joggle1412to form a smooth aerodynamic transition at an area1732near the joggle1412. In such implementations, an aerodynamic filler is not utilized or a size of the aerodynamic filler is reduced. The aerodynamic transition is relatively smoother and imparts less drag than aerodynamic transitions between the transcowl124and cantilevered portion144without a joggle1412, such as a cantilevered portion having a cross-section that is substantially straight or is straight in a longitudinal axis (e.g., fore to aft). In other implementations, the acoustic panel132is coupled to another component of a nacelle, a vehicle, or an aircraft, such as the aircraft100ofFIG. 1.

FIG. 18illustrates a particular example of a method1800for controlling generating an acoustic panel, such as the acoustic panel132ofFIG. 1. The method1800may be performed by computer (e.g., a controller of a composite part fabrication system).

The method1800includes, at1802, applying a layer of composite material to a base, the base having a surface defining a plurality of cavities. For example, the layer of composite material may include or correspond to the first layer of composite material812ofFIG. 8or the second layer of composite material818ofFIG. 8. The base may include or correspond to the base142ofFIG. 1. To illustrate, the first layer of composite material812is deposited (e.g., directly deposited) on the base142or the second layer of composite material818is deposited on the base142and is in contact with the first layer of composite material812.

The method1800includes, at1804, applying a layup support member to the layer of composite materials. For example, the layup support member may include or correspond to the layup support member1112ofFIG. 11. To illustrate, the layup support member1112is placed on the base142(or the first layer of composite material818) before curing (e.g., by a first cure or a second cure) the pre-cured composite component1216to the base142, as described with reference toFIG. 12.

The method1800also includes, at1806, forming a cantilevered portion extending from the base. The layup support material is positioned between the base and the cantilevered portion. After forming the cantilevered portion, the cantilevered portion is configured to be coupled to and support another component. A portion of a surface of the cantilevered portion is an aerodynamic surface, as described with reference toFIG. 8.FIG. 18illustrates two exemplary method of forming1806the cantilevered portion144in dashed boxes.

In some implementations, forming1806includes applying1812second composite material to the layer of composite material and the layup support member. The layup support material is positioned between the base and the second composite material. The second composite material may include or correspond to uncured (e.g., “green”) CFRP plies, as described with reference toFIG. 11. For example, the uncured CFRP plies are placed (laid-up) on the support material1012and the second layer of composite material818(which is supported by the layup support member1112).

In such implementations, forming1806also includes placing1814a caul plate on the second composite material and curing1816the layer of composite material and the second composite material to form the cantilevered portion. To illustrate, a caul plate is placed on top of the uncured CFRP plies. Heat and pressure are applied to the caul plate which transfers the heat and pressure to cure the uncured CFRP plies and one or more layers of composite material812,818to form the cantilevered portion144and secure it to the base142. After curing, the caul plate is removed.

In other implementations, forming1806includes applying1822a pre-cured composite component to the layer of composite material and the layup support member to form a cantilevered portion extending from the base. The layup support member is positioned between the base and the cantilevered portion. For example, the pre-cured composite component may include or correspond to the cantilevered portion144ofFIG. 1, the doubler816ofFIG. 8, the pre-cured composite component1216ofFIG. 1, or a combination thereof. To illustrate, the pre-cured composite component1216is placed on the layup support member1112and the support member146or the support material1012, as described with reference toFIG. 12. Curing one or more layers of composite material812,818affixes the pre-cured composite component1216to the base142to form the doubler816which includes a portion that is attached to the base142(e.g., via the first layer of composite material812) and a portion that extends from the base142, i.e., the cantilevered portion144.

In such implementations where the pre-cured composite component is used, forming1806further includes curing1824the layer of composite material to fixedly couple the pre-cured composite component to the base. For example, heat and pressure is applied to cure the first layer of composite material812, the second layer of composite material818, or both, to fixedly adhere the pre-cured composite component1216to the base142, as described with reference toFIG. 12.

Adhering the pre-cured composite component1216to the base142generates a cantilevered portion144for joining another component (e.g., a portion of the transcowl124) and enlarges an active acoustic area of the base142(e.g., prevents reduction of an acoustically active area caused by fasteners joining the acoustic panel132and the other component). Additionally, the acoustic panel132may be easily disconnected from the other component because of the use of fasteners not penetrating the base142(as opposed to adhesives, such as fasteners assemblies1702,1704) which improves repairability, aerodynamic performance, and acoustic performance (especially after repair or maintenance of the nacelle that requires disassembly to the acoustic panel132and the transcowl124).

In some implementations, the cantilevered portion is fixedly coupled or fixedly adhered to the base. Additionally, the support member may be fixedly coupled or fixedly adhered to the base, the cantilevered portion, or both. For example, the base142, the cantilevered portion144, and the support member146form a monolithic structure.

In some implementations, one or more fasteners extend through the cantilevered portion and the portion of the transcowl to couple the cantilevered portion to the portion of the transcowl. For example, one or more nut plates1724are fastened to the cantilevered portion144, and the cantilevered portion144is joined with the portion of the transcowl124via bolts1712extending through the portion of the transcowl124and threading with the nut plate1724.

In some implementations, the plurality of cavities, such as the plurality of cavities722ofFIG. 7B, have a hexagonal shape (e.g., a honeycomb shape). In other implementations, the plurality of cavities has a circular shape, a rectangular shape, a square shape, a pentagonal shape, an octagonal shape, or a combination thereof, as described with reference toFIG. 7B.

In some implementations, the cantilevered portion has a joggled portion to receive the portion of the transcowl. For example, the cantilevered portion144is a joggled, notched, or faired in cantilevered portion144(e.g., includes the joggle1412) and maintains aerodynamic smoothness when coupled with the transcowl124, as illustrated inFIGS. 14 and 17. In other implementations, the cantilevered portion144has a longitudinal cross-section that is substantially straight or is straight in a longitudinal axis (e.g., fore to aft), as illustrated inFIGS. 8 and 15. Additional or alternatively, the cantilevered portion144is tapered, as illustrated inFIGS. 8 and 14. For example, the distal end834of the doubler816(or the pre-cured composite component1216) is thicker than the proximal end832of the doubler816(or the pre-cured composite component1216).

In some implementations, the support member includes or corresponds to a noodle, such as the noodle814ofFIGS. 8 and 14. In a particular implementation, the noodle814includes or corresponds to a material having a similar elasticity to carbon fiber reinforced polymer of the cantilevered portion144. In other implementations, the support member includes or corresponds to a molded insert, such as the molded insert1512ofFIGS. 15 and 16. In a particular implementation, the molded insert includes or corresponds to a thermoplastic material or a thermoset polymer material.

In some implementations, the engine (e.g., the propulsor112) is configured to generate thrust, and the thrust reversal assembly (e.g., the thrust reverser116) is configured to redirect a portion of the thrust generated by the engine to generate second thrust (and/or increase drag) that partially opposes the thrust, as described with reference toFIG. 1.

In some implementations, the method1800further includes removing the layup support member and inserting a support material into a cavity positioned between the layer of composite material and the cantilevered portion, as described with reference toFIGS. 10 and 13.

In some implementations, the method1800further includes applying a second layer of composite material to the layer of composite material, the support material, and the cantilevered portion and curing the second layer of composite material to couple the cantilevered portion (e.g., the pre-cured composite component), the support material, and the layer of composite material, as described with reference toFIGS. 11-13.

In some implementations, the layer of composite material is applied to a first surface of the base. In some such implementations, the method1800further includes applying a third layer of composite material to a second surface of the base. The second surface opposite the first surface and corresponding to a first aerodynamic surface. The first surface and a surface of the cantilevered portion (e.g., the pre-cured composite component) correspond to a second aerodynamic surface, as described with reference toFIGS. 5, 8, and 9.

In some implementations, the method1800further includes, prior to applying the pre-cured composite component to the base applying carbon fiber reinforced polymer to a tool and curing (or partially curing) the carbon fiber reinforced polymer to generate the pre-cured composite component, as described with reference toFIG. 12. In a particular implementation, the pre-cured composite component (or doubler) is tapered, as described with reference toFIG. 8.

The methods1800ofFIG. 18may be initiated or controlled by an application-specific integrated circuit (ASIC), a processing unit, such as a central processing unit (CPU), a controller, another hardware device, a firmware device, a field-programmable gate array (FPGA) device, or any combination thereof. As an example, the method1800ofFIG. 18can be initiated or controlled by one or more processors, such as one or more processors included in a control system. In some implementations, a portion of the method1800ofFIG. 18may be combined with a second portion of the method1800ofFIG. 18. Additionally, one or more operations described with reference toFIG. 18may be optional and/or may be performed in a different order than shown or described. Two or more operations described with reference toFIG. 18may be performed at least partially concurrently.

Referring toFIGS. 19 and 20, examples of the disclosure are described in the context of a vehicle manufacturing and service method1900as illustrated by the flow chart ofFIG. 19and a vehicle2002as illustrated by the block diagram2000ofFIG. 20. A vehicle produced by the vehicle manufacturing and service method1900ofFIG. 19, such as the vehicle2002ofFIG. 20, may include an aircraft, an airship, a rocket, a satellite, a submarine, or another vehicle, as illustrative, non-limiting examples. The vehicle2002may be manned or unmanned (e.g., a drone or an unmanned aerial vehicle (UAV)).

Referring toFIG. 19, a flowchart of an illustrative example of a method of acoustic panel manufacturing and service is shown and designated1900. During pre-production, the exemplary method1900includes, at1902, specification and design of a vehicle, such as a vehicle2002described with reference toFIG. 20. During the specification and design of the vehicle2002, the method1900may include specifying a design of an acoustic panel, such as the acoustic panel132ofFIG. 1. At1904, the method1900includes material procurement. For example, the method1900may include procuring materials for the acoustic panel132of the vehicle2002.

During production, the method1900includes, at1906, component and subassembly manufacturing and, at1908, system integration of the vehicle2002. The method1900may include component and subassembly manufacturing (e.g., manufacturing the acoustic panel132ofFIG. 1) of the vehicle2002and system integration (e.g., coupling the acoustic panel132ofFIG. 1to one or more components of the vehicle2002, such as the transcowl124). At1910, the method1900includes certification and delivery of the vehicle2002and, at1912, placing the vehicle2002in service. Certification and delivery may include certifying the acoustic panel132ofFIG. 1by inspection or non-destructive testing. While in service by a customer, the vehicle2002may be scheduled for routine maintenance and service (which may also include modification, reconfiguration, refurbishment, and so on). At1914, the method1900includes performing maintenance and service on the vehicle2002. The method1900may include performing maintenance and service of the propulsor112, the thrust reverser116, or the acoustic panel132ofFIG. 1. For example, maintenance and service of the propulsor112may include decoupling the acoustic panel132from the transcowl124or replacing the acoustic panel132.

Referring toFIG. 20, a block diagram2000of an illustrative implementation of the vehicle2002that includes an acoustic panel, such as the acoustic panel132ofFIG. 1. To illustrate, the vehicle2002may include an aircraft, such as the aircraft100ofFIG. 1, as an illustrative, non-limiting example. The vehicle2002may have been produced by at least a portion of the method1900ofFIG. 19. As shown inFIG. 20, the vehicle2002(e.g., the aircraft100ofFIG. 1) includes an airframe2018, an interior2022, the nacelle102, and a plurality of systems2020. The plurality of systems2020may include one or more of a propulsion system2024, an electrical system2026, an environmental system2028, or a hydraulic system2030. The nacelle102includes the acoustic panel132, and the acoustic panel132includes the base142, the cantilevered portion144, and the support member146. The acoustic panel132may be manufactured by one or more steps of the method1800ofFIG. 18and/or as described with reference toFIGS. 9-13.

Apparatus and methods included herein may be employed during any one or more of the stages of the method1900ofFIG. 19. For example, components or subassemblies corresponding to production process1908may be fabricated or manufactured in a manner similar to components or subassemblies produced while the vehicle2002is in service, at1912for example and without limitation. Also, one or more apparatus implementations, method implementations, or a combination thereof may be utilized during the production stages (e.g., stages1902-1910of the method1900), for example, by substantially expediting assembly of or reducing the cost of the vehicle2002. Similarly, one or more of apparatus implementations, method implementations, or a combination thereof, may be utilized while the vehicle2002is in service, at1912for example and without limitation, to maintenance and service, at1914.

The illustrations of the examples described herein are intended to provide a general understanding of the structure of the various implementations. The illustrations are not intended to serve as a complete description of all of the elements and features of apparatus and systems that utilize the structures or methods described herein. Many other implementations may be apparent to those of skill in the art upon reviewing the disclosure. Other implementations may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. For example, method operations may be performed in a different order than shown in the figures or one or more method operations may be omitted. Accordingly, the disclosure and the figures are to be regarded as illustrative rather than restrictive.