Patent Application
20230167774
The present disclosure relates generally to attenuation structures for reducing acoustic noise and, more particularly, to inner barrels for reducing noise generated within engines or propulsion systems.
Some fan compartments for gas turbine engines may include fire zones. In this regard, an inlet aft bulkhead and an attachment ring may define a fire barrier. Attachment rings may be made of metal, or metal alloys. Thus, the attachment rings may withstand heat, but also conduct heat to various components. An inner barrel of a fan compartment may be constructed of composite materials and have a limited temperature exposure threshold (e.g., 350° F.). Current methods for thermally protecting the inner barrel and the attachment ring include heat blankets, coatings, and/or shields, which are typically heavy, costly, and/or include maintainability burdens.
An inner barrel is disclosed herein. The inner barrel may comprise: a perforated top sheet; a backskin; a core disposed between the perforated top sheet and the backskin; and an insulator coupled to the backskin, the insulator comprising a polymeric material.
In various embodiments, the insulator comprises one of ethylene propylene diene monomer (EPDM), neoprene, styrene butadiene rubber (SBR), natural rubber, urethane rubber, and silicone rubber. The inner barrel may further comprise an adhesive disposed between the insulator and the backskin. The insulator may comprise a hardness of at least Shore A 70. A nacelle may comprise the inner barrel.
A nacelle inlet is disclosed herein. The nacelle inlet may comprise: an inner barrel at least partially defining a flow path on a radially inner surface, the inner barrel comprising an insulator disposed radially outward from the radially inner surface; and an attachment ring coupled to the inner barrel, the attachment ring disposed adjacent to, and in contact with the insulator.
The insulator may comprise a hardened polymeric material. The hardened polymeric material may comprise a hardness between Shore A 70 and Shore A 100. The inner barrel may comprise a backskin, a perforated top sheet, and a core disposed between the backskin and the perforated top sheet. The perforated top sheet may define the radially inner surface of the inner barrel. The insulator may be coupled to the backskin. The nacelle inlet may further comprise an adhesive disposed between the backskin and the insulator. The insulator may be configured to reduce heat propagation from an interior cowl cavity radially inward from the attachment ring during a fire event within the nacelle inlet.
A method of manufacture for an inner barrel of a nacelle is disclosed herein. The method of manufacture may comprise: laying up an elastomeric material on a backskin of an inner barrel to form a pre-cure assembly; heating the pre-cure assembly; and pressurizing the pre-cure assembly to cure the pre-cure assembly and harden the elastomeric material.
In various embodiments, pressurizing the pre-cure assembly forms a hardened polymeric material on the backskin of the inner barrel. The method may further comprise: laying up a perforated top sheet; laying up a core with an adhesive on the perforated top sheet; and laying up the backskin prior to laying up the elastomeric material. Pressurizing the pre-cure assembly may further comprise curing the pre-cure assembly with a mold having a contour of the inner barrel. The mold may form a contour for an insulator defining a radially outer surface of the inner barrel. The method may further comprise coupling an attachment ring to the radially outer surface. The elastomeric material may comprise one of ethylene propylene diene monomer (EPDM), neoprene, styrene butadiene rubber (SBR), natural rubber, urethane rubber, and silicone rubber.
The foregoing features and elements may be combined in any combination, without exclusivity, unless expressly indicated herein otherwise. These features and elements as well as the operation of the disclosed embodiments will become more apparent in light of the following description and accompanying drawings.
The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the following detailed description and claims in connection with the following drawings. While the drawings illustrate various embodiments employing the principles described herein, the drawings do not limit the scope of the claims.
The following detailed description of various embodiments herein makes reference to the accompanying drawings, which show various embodiments by way of illustration. While these various embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that changes may be made without departing from the scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. It should also be understood that unless specifically stated otherwise, references to “a,” “an” or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. Further, all ranges may include upper and lower values and all ranges and ratio limits disclosed herein may be combined.
As used herein, “aft” refers to the direction associated with the tail (e.g., the back end) of an aircraft, or generally, to the direction of exhaust of the gas turbine. As used herein, “forward” refers to the direction associated with the nose (e.g., the front end) of an aircraft, or generally, to the direction of flight or motion.
As used herein, “distal” refers to the direction radially outward, or generally, away from the axis of rotation of a turbine engine. As used herein, “proximal” refers to a direction radially inward, or generally, towards the axis of rotation of a turbine engine.
As used herein, “outboard” may define an element or portion of an element that is situated radially outer to or away from another, radially inward, element or portion of an element. Thus, an engine core may be situated radially inboard of an inner fixed structure (“IFS”) and/or a fan casing, as described herein. As used herein, “inboard” may define the element or portion of the element that is situated radially inward in relation to an outboard element.
Insulator systems disclosed herein may allow a larger design space for the aft portion of an inlet of a nacelle. Insulator systems disclosed herein may reduce weight by removing extra heat blankets, fire/radiation shields, coatings, or the like. Insulator systems disclosed herein may also be applicable for heat conduction sensitive joints in a gas turbine engine, such as a bumper connection to the IFS composite panels.
According to various embodiments,
Core engine 120 drives a fan 114 arranged in a bypass flow path 124. Bypass air flow B, driven by the fan 114, flows in the aft direction through bypass flow path 124. At least a portion of bypass flow path 124 may be defined by nacelle structure 112 and inner fixed structure (IFS) 126. As is known, the general shape of IFS 126 is a surface of revolution around the engine axis, often with two bifurcation panels at the six o'clock and the twelve o'clock position which extend radially outward, and the IFS 126 is often made from two generally mirror image halves that hinge together as part of the thrust reverser structure. The radially outboard surface of IFS 126 may be referred to as an inner flow surface 136 of the bypass flow path 124, and the radially inboard surface of nacelle structure 112 may be referred to as an outer flow surface 138 of the bypass flow path 124. Fan case 132 may surround fan 114. Fan case 132 may be housed within nacelle structure 112.
In various embodiments, an intermediate case (IMC) 134 of the gas turbine engine 110 may be provided radially inward of fan case 132. Fan case 132 may provide a mounting structure for securing gas turbine engine 110 to a pylon. IMC 134 may be surrounded by nacelle structure 112. According to various embodiments, multiple guide vanes 116 may extend radially between fan case 132 and IMC 134. Core engine 120 may be secured to fan case 132 at IMC 134.
In various embodiments, a nacelle inlet 130 of the nacelle structure 112 may be provided axially forward of the fan case 132. Nacelle inlet 130 may comprise an aft bulkhead 102 and an attachment ring 104 coupled to the aft bulkhead 102 whereby nacelle inlet 130 is coupled to fan case 132. An inner barrel 106 may be coupled to attachment ring 104. Inner barrel 106 may at least partially define bypass flow path B.
According to various embodiments,
In various embodiments, nacelle inlet 200 comprises an inner barrel 230 (i.e., an inner barrel). Inner barrel 230 may be coupled to attachment ring 220. Attachment ring 220 may comprise a second plurality of apertures 284 disposed therein whereby a plurality of fasteners—e.g., bolts, rivets, or the like—may secure inner barrel 230 to attachment ring 220. Mechanical loads may be transferred between inner barrel 230 and attachment ring 220, via the plurality of fasteners at second plurality of apertures 284. Inner barrel 230 may be acoustically treated in a single degree of freedom (SDOF), double degree of freedom (DDOF), or other acceptable arrangement.
In various embodiments, the inner barrel 230 comprises an insulator as described further herein. In this regard, the inner barrel 230 is configured to at least partially thermally insulate the attachment ring 220 and/or the aft bulkhead 210 from a high heat source—e.g., fire, bleed air, or the like—internal to the cowl, radially outward from the inner barrel.
Referring to
Referring now to
In various embodiments, the insulator 340 may be coupled to the backskin 330 during the manufacturing process of the inner barrel 230. For example, the insulator 340 being coupled to the backskin 330 during a manufacturing process of the inner barrel 230 is illustrated in
Referring now to
In various embodiments, the process further comprises curing the assembly (as shown in
In various embodiments, the machining step in
In various embodiments, the hardness for the insulator 340 from
Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials.
Systems, methods and apparatus are provided herein. In the detailed description herein, references to “one embodiment,” “an embodiment,” “various embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.
Numbers, percentages, or other values stated herein are intended to include that value, and also other values that are about or approximately equal to the stated value, as would be appreciated by one of ordinary skill in the art encompassed by various embodiments of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least the variation to be expected in a suitable industrial process, and may include values that are within 10%, within 5%, within 1%, within 0.1%, or within 0.01% of a stated value. Additionally, the terms “substantially,” “about” or “approximately” as used herein represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the term “substantially,” “about” or “approximately” may refer to an amount that is within 10% of, within 5% of, within 1% of, within 0.1% of, and within 0.01% of a stated amount or value.
Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Finally, it should be understood that any of the above described concepts can be used alone or in combination with any or all of the other above described concepts. Although various embodiments have been disclosed and described, one of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. Accordingly, the description is not intended to be exhaustive or to limit the principles described or illustrated herein to any precise form. Many modifications and variations are possible in light of the above teaching.
