Patent ID: 12234987

DETAILED DESCRIPTION

Features, advantages, and embodiments of the present disclosure are set forth or apparent from a consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that the following detailed description is exemplary and intended to provide further explanation without limiting the scope of the disclosure as claimed.

Various embodiments are discussed in detail below. While specific embodiments are discussed, this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and the scope of the present disclosure.

As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows.

The terms “coupled,” “fixed,” “attached,” “connected,” and the like, refer to both direct coupling, fixing, attaching, or connecting, as well as indirect coupling, fixing, attaching, or connecting through one or more intermediate components or features, unless otherwise specified herein.

The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.

Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” “generally,” and “substantially” is not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or the machines for constructing the components and/or the systems or manufacturing the components and/or the systems. For example, the approximating language may refer to being within a one, two, four, ten, fifteen, or twenty percent margin in either individual values, range(s) of values and/or endpoints defining range(s) of values.

A cowl and the annular dome assembly of the combustor of the gas turbine engine may be attached, mounted, or otherwise connected to the liner assembly by, for example, one or more bolts. During operation of the gas turbine engine, the liner assembly, and a deflector of the annular dome assembly, experience high thermal gradients due to hot combustion products (e.g., hot combustion gases) in the combustion chamber. In addition to the high thermal gradients, vibrations may propagate from the connection of the cowl, the annular dome assembly, and the liner assembly. The vibrations may propagate through the liner assembly and, in combination with the high thermal gradients, may cause mechanical stress on the liner assembly both at the connection and downstream of the connection. Accordingly, the liner assembly may eventually fail prior to a complete designed lifecycle of the liner assembly. Thus, embodiments of the present disclosure provide for an improved liner assembly for the combustor to improve durability and a lifecycle of the liner assembly compared to liner assemblies without the benefit of the present disclosure.

The liner assembly of the present disclosure may include a looped section at a forward end thereof. The looped section may be bolted or otherwise fastened with the cowl and the dome. The looped section may be shaped to include one or more bends (e.g., U-shaped, Omega-shaped, hairpin bend, etc.) provided in the liner assembly (e.g., in the support shell). The looped section may include a compliant joint, also referred to as a flexure joint or a flexible joint. As used herein, a “compliant joint,” a “flexure joint,” and/or a “flexible joint” may include a connection that provides multiple degrees of freedom between connected parts of a monolithic structure. For example, the compliant joint provided by the looped section (e.g., via the one or more bends) may help to avoid, to reduce, or to prevent vibrations and/or to avoid, to reduce, or to prevent other mechanical stresses from propagating downstream of the looped section. Thus, the looped section may improve durability of the liner assembly and increase a lifecycle of the liner assembly as compared to liner assemblies without the benefit of the present disclosure.

The looped section may include an air cavity formed therein. The air cavity may receive cooling air from the compressor section of the gas turbine engine. The feed into the air cavity may be metered and downstream holes may be used to direct the cooling air from the air cavity. In this way, the air cavity may act as an acoustic damper to further dampen vibrations and mechanical stress. The looped section, and, therefore, the air cavity, may be shaped to achieve a designed frequency.

The bolts may be inserted through a hole in a radially outer portion of the looped section such that the bolts may be disposed within the air cavity. Submerging the bolts in the air cavity in this way may provide for improved aerodynamic feed into the air cavity. The holes for the bolts may be sealed to prevent or to control air flow using a U-shaped washer or a similar seal. The volume of the air cavity, a length of a neck of the looped section, and an area of an opening of the neck may be sized and/or shaped to tune the looped section to a specific frequency, as desired. The air cavity may include a single annular cavity and/or may include one or more partitions in a radial, an axial, and/or a circumferential direction such that the air cavity is partitioned into separate cavities. The looped section may also include a hairpin bend to direct cooling air towards the dome and to create an additional damping cavity. The looped section may also include one or more acoustic feed holes to further provide for acoustic damping.

The downstream holes may be sized, shaped, and/or angled to direct the cooling air in a desired direction. For example, the air flow from the air cavity may be used to film cool the support shell and/or the heat shield to help further improve durability of the liner assembly. The flow from the air cavity may also be directed to impinge and to provide cooling on the corners of the dome and/or the deflector assembly. For example, a downstream bend in the looped section may include holes to direct the air flow onto bolts of the deflector assembly. The holes can include any size, shape, and/or angle for directing the flow in a desired direction. The air cavity may include metered holes (e.g., discrete holes) and/or a metered annular opening therein to provide a feed of cooling air into the air cavity. The holes may include one row of holes and/or may include multiple rows.

The looped section at the forward end of the liner assembly may control leakage of cooling air and direct the cooling air along a hot side of the liner assembly. The cowl may be shaped such that it couples with the looped section to provide for a compliant joint, as detailed above. The cowl may be extended to provide for cooling holes and to control leakage on the forward end of the liner assembly. The ratio of the air cavity volume to the cowl volume may be between zero percent to fifty percent. The radius and/or the diameter of the cowl may be sized to keep a distance between an outer combustor casing and the cowl the same as in embodiments without the benefit of the present disclosure. The cooling air directed to the bolts of the deflector assembly may be directed in a radial direction. In some embodiments, the cooling air directed to the bolts of the deflector assembly may be directed tangentially with respect to the bolts.

Referring now to the drawings,FIG.1is a schematic partial cross-sectional view of a portion of an exemplary combustion section26having a deflector assembly160used in a gas turbine engine system, as may incorporate various embodiments of the present disclosure. Gas turbine engine systems may include any suitable configuration, such as, but not limited to, turbofan, turboprop, turboshaft, turbojet, or prop-fan configurations for aviation, marine, or power generation purposes. Still further, other suitable configurations may include steam turbine engines or another Brayton cycle machine. Various embodiments of the combustion section26may further define a rich burn combustor. Other embodiments may, however, define a lean burn combustor configuration. In the exemplary embodiment, the combustion section26includes an annular combustor. One skilled in the art will appreciate that the combustor may be any other combustor, including, but not limited to, a single annular combustor or a double annular combustor, a can-combustor, or a can-annular combustor.

As shown inFIG.1, the combustion section26defines an axial direction A and a radial direction R that is normal to the axial direction A. The combustion section26includes an outer liner assembly102and an inner liner assembly104disposed between an outer combustor casing106and an inner combustor casing108. The outer liner assembly102and the inner liner assembly104are spaced radially from each other such that a combustion chamber110is defined therebetween. The outer liner assembly102and the outer combustor casing106form an outer passage112therebetween, and the inner liner assembly104and the inner combustor casing108form an inner passage114therebetween.

The combustion section26may also include a combustor assembly118comprising an annular dome assembly120mounted upstream of the combustion chamber110. The combustor assembly118is configured to be coupled to the forward ends of the outer liner assembly102and the inner liner assembly104. More particularly, the combustor assembly118includes an inner annular dome122attached to the forward end of the inner liner assembly104and an outer annular dome124attached to the forward end of the outer liner assembly102.

The combustion section26may be configured to receive an annular stream of compressor discharge air126from a discharge outlet of a high-pressure compressor (not shown) of the gas turbine engine system. To assist in directing the compressed air (e.g., compressor discharge air126), the annular dome assembly120may further comprise an inner cowl128and an outer cowl130that may be coupled to the upstream ends of the inner liner assembly104and the outer liner assembly102, respectively. In this regard, an annular opening132formed between the inner cowl128and the outer cowl130enables compressed fluid to enter combustion section26through a diffuse opening in a direction generally indicated by flow direction134. The compressed air may enter into a cavity136defined at least in part by the annular dome assembly120. In various embodiments, the cavity136is more specifically defined between the inner annular dome122and the outer annular dome124, and the inner cowl128and the outer cowl130. As will be discussed in more detail below, a portion of the compressed air in the cavity136may be used for combustion, while another portion may be used for cooling the combustion section26.

In addition to directing air into the cavity136and the combustion chamber110, the inner cowl128and the outer cowl130may direct a portion of the compressed air around the outside of the combustion chamber110to facilitate cooling the outer liner assembly102and the inner liner assembly104. For example, as shown inFIG.1, a portion of the compressor discharge air126may flow around the combustion chamber110, as indicated by an outer passage flow direction138and an inner passage flow direction140, to provide cooling air to the outer passage112and the inner passage114, respectively. A first distance105may be defined between the outer cowl130and the outer combustor casing106, and a second distance107may be defined between the inner cowl128and the inner combustor casing108. The first distance105and the second distance107may be sized, as desired, to control an amount of cooling air directed by the outer cowl130and the inner cowl128around the outside of the combustion chamber110, respectively.

In certain exemplary embodiments, the inner annular dome122may be formed integrally as a single annular component, and, similarly, the outer annular dome124may also be formed integrally as a single annular component. In still certain embodiments, the inner annular dome122and the outer annular dome124may together be formed as a single integral component. In still various embodiments, the annular dome assembly120, including one or more of the inner annular dome122, the outer annular dome124, the outer liner assembly102, or the inner liner assembly104, may be formed as a single integral component. In other exemplary embodiments, the inner annular dome122and/or the outer annular dome124may alternatively be formed by one or more components joined in any suitable manner. For example, with reference to the outer annular dome124, in certain exemplary embodiments, the outer cowl130may be formed separately from the outer annular dome124and attached to the forward end of the outer annular dome124using, e.g., a welding process, a mechanical fastener, a bonding process or adhesive, or a composite layup process. Additionally, or alternatively, the inner annular dome122may have a similar configuration.

The combustor assembly118further includes a plurality of mixer assemblies142spaced along a circumferential direction between the outer annular dome124and the inner annular dome122. In this regard, the annular dome assembly120defines an opening in which a swirler, a cyclone, or a mixer assembly142is mounted, attached, or otherwise integrated for introducing the air/fuel mixture into the combustion chamber110. Notably, compressed air (e.g., compressor discharge air126) may be directed into or through one or more of the mixer assemblies142to support combustion in the upstream end of the combustion chamber110.

A liquid fuel and/or a gaseous fuel is transported to the combustion section26by a fuel distribution system (not shown), where it is introduced at the front end of a burner in a highly atomized spray from a fuel nozzle. In an exemplary embodiment, each mixer assembly142may define an opening for receiving a fuel injector146(details are omitted for clarity). The fuel injector146may inject fuel in a generally axial direction A, as well as in a generally radial direction R, where the fuel may be swirled with the incoming compressed air. Thus, each mixer assembly142receives compressed air from the annular opening132and fuel from a corresponding fuel injector146. Fuel and pressurized air are swirled and mixed together by the mixer assemblies142, and the resulting fuel/air mixture is discharged into combustion chamber110for combustion thereof.

The combustion section26may further comprise an ignition assembly (e.g., one or more igniters extending through the outer liner assembly102) suitable for igniting the fuel-air mixture. Details of the fuel injectors and the ignition assembly are omitted inFIG.1for clarity. Upon ignition, the resulting hot combustion gases may flow in a generally axial direction through the combustion chamber110into and through the turbine section of the engine where a portion of thermal and/or kinetic energy from the hot combustion gases is extracted via sequential stages of turbine stator vanes and turbine rotor blades. More specifically, the hot combustion gases may flow into an annular, first stage turbine nozzle148. As is generally understood, the first stage turbine nozzle148may be defined by an annular flow channel that includes a plurality of radially extending, circularly spaced nozzle vanes150that turn the gases so that they flow angularly and impinge upon the first stage turbine blades of a high-pressure turbine of the gas turbine engine system.

Referring still toFIG.1, the plurality of mixer assemblies142are placed circumferentially within the annular dome assembly120. Fuel injectors146are disposed in each mixer assembly142to provide fuel and to support the combustion process. Each dome has a heat shield, for example, a deflector assembly160that thermally insulates the annular dome assembly120from the extremely high temperatures generated in the combustion chamber110during engine operation (e.g., from the hot combustion gases). The inner annular dome122, the outer annular dome124, and the deflector assembly160may define a plurality of openings144for receiving the mixer assemblies142. As shown, the plurality of openings144are, in one embodiment, circular. In other embodiments, the openings144are ovular, elliptical, polygonal, oblong, or other non-circular cross sections. The deflector assembly160is mounted on a combustion chamber side (e.g., a downstream side) of the annular dome assembly120. The deflector assembly160may include a plurality of panels, as detailed further below.

Compressed air (e.g., compressor discharge air126) flows into the annular opening132where a portion of the compressor discharge air126will be used to mix with fuel for combustion and another portion will be used for cooling the deflector assembly160. Compressed air may flow around the fuel injector146and through the mixing vanes around the circumference of the mixer assemblies142, where compressed air is mixed with fuel and directed into the combustion chamber110. Another portion of the air enters into the cavity136defined by the annular dome assembly120, the inner cowl128, and the outer cowl130. The compressed air in the cavity136is used, at least in part, to cool the annular dome assembly120and the deflector assembly160, as detailed further below.

FIG.2is a schematic partial cross-sectional view of a forward end103, or an upstream end, of the outer liner assembly102, taken at detail2inFIG.1. While the exemplary embodiments detailed herein refer to the outer liner assembly102, embodiments of the present disclosure are also applicable to the inner liner assembly104. As shown inFIG.2, the outer liner assembly102may include a support shell, also referred to as a liner202, and a heat shield204. In the exemplary embodiments, the liner202may be generally cylindrical, but may take any known shape of a liner for a combustor. The heat shield204may include one or more tiles or panels206arranged on and coupled to a hot side of the liner202. That is, the panels206of the heat shield204may be coupled on a side of the liner202exposed to the combustion chamber110(FIG.1). Two panels206of the heat shield204are depicted inFIG.2but the heat shield204may include any number of panels206, as desired. The liner202may be non-ceramic. In some examples, the liner202may be a metal liner. The panels206of the heat shield204may be ceramic. In some examples, the panels206may be ceramic matrix composites (CMC). Thus, the heat shield204may provide a shield for the liner202, enhancing the life of the liner202.

The outer liner assembly102may include a one or more fastening mechanisms (not shown) for attaching and connecting the liner202and the panels206of the heat shield204. That is, each of the panels206is coupled by the one or more fastening mechanisms to the liner202. The fastening mechanisms may include any type of known fastening mechanism such as, for example, bolts, screws, nuts, rivets, brazing, welding, or the like. A gap or a space208may be located between a radially outer surface of each of the panels206and a radially inner surface of the liner202. The space208may be formed due to the fastening mechanisms. Each of the panels206may include one or more panel walls210extending from a radially outer surface of each of the panels206. When the panels206of the heat shield204are attached, connected, or otherwise mounted to the liner202, the panel walls210may extend to, and contact, the radially inner surface of the liner202. The liner202and the heat shield204may each include one or more cooling holes respectively therethrough for providing cooling air to portions of the combustion chamber110(FIG.1), as detailed further below.

The outer annular dome124and the outer cowl130may be attached or otherwise mounted to the outer liner assembly102at the forward end103or the upstream end of the outer liner assembly102. For example, the outer annular dome124and the outer cowl130may be attached to the forward end103of the liner202of the outer liner assembly102. One or more fastening mechanisms212may fasten the outer annular dome124and the outer cowl130to the forward end103of the liner202. In some instances, the liner202may be exposed to high mechanical and thermal stresses around an area of the fastening mechanisms212(e.g., at the forward end103of the liner202) in outer liner assemblies without the benefit of the present disclosure. Thus, the present disclosure provides for a liner202having a looped section at the forward end103of the liner202, as detailed further below.

InFIG.2, the liner202may include a looped section220that defines the forward end103of the liner202. The looped section220may include one or more bends222in the liner202to form the looped section220. For example, the liner202may include a unitary length of liner202bent at a first bend222ato form an elongated U-shape or an elongated C-shape defining the looped section220. In this way, the first bend222amay form a smoothly curved, arcuate configuration. The first bend222amay include a first diameter. The size (e.g., the first diameter) and/or the shape of the first bend222amay include any size and/or shape, as desired, for forming the looped section220at the forward end103of the liner202. The first bend222amay include a first portion223and a second portion225. The first bend222amay be oriented such that the first portion223is a radially inner portion and the second portion225is a radially outer portion.

The looped section220may include a free wall224, e.g., a wall with a free end226, and a connecting wall228. The free wall224may extend from the first portion223of the first bend222aand the connecting wall228may extend from the second portion225of the first bend222a. For example, the free wall224and the connecting wall228may each merge into the first bend222aat the first portion223and the second portion225, respectively. In this way, the connecting wall228may be spaced radially from the free wall224and a cavity230may be defined between the connecting wall228and the free wall224. The cavity230may include a height or a diameter defined between the free wall224and the connecting wall228. The cavity230may also include a volume. Thus, the connecting wall228may define a radially outer portion of the looped section220and the free wall224may define a radially inner portion of the looped section220. The free wall224and the connecting wall228may preferably be generally rectilinear, but are not limited to such a straight-line configuration. The looped section220may be partitioned (e.g., by one or more walls) axially, radially, and/or circumferentially such that the looped section220may include one or more partitions.

An axial length of the free wall224may include a length such that the free wall224extends from the first bend222ato adjacent a distal end of the outer cowl130. The free wall224may include an axial length that extends beyond (e.g., axially distal) the distal end of the outer cowl130and/or an axial length that extends axially proximal the distal end of the outer cowl130. The connecting wall228may include a length that extends from the first bend222ato a proximal end of an axially extending portion203of the liner202. The axial length of the free wall224and the connecting wall228may include a length such that the first bend222ais positioned axially adjacent to a bent portion of the outer cowl130when the outer cowl130is mounted to the liner202.

The connecting wall228may be connected to the axially angled portion203of the liner202. In this way, the looped section220may form a unitary structure of the liner202. In some examples, the looped section220may be formed separately from the axially angled portion203of the liner202and may be connected to or attached to the axially angled portion203by brazing, welding, or the like. A connecting bend221may be formed between the connecting wall228and the axially angled portion203of the liner202. The connecting bend221may direct the shape of the liner202from the axially angled portion203to the connecting wall228such that the connecting wall228extends substantially axially (e.g., rectilinear). The connecting bend221may include any size and/or shape, as desired, for forming a smooth transition between the axially angled portion203and the connecting wall228.

The free wall224includes one or more second bends222b. The one or more second bends222bmay be located at an axially distal end of the free wall224. InFIG.2, the one or more second bends222binclude two second bends222bsuch that the axially distal end of the free wall224defines a distal bent portion227. The distal bent portion227includes a first angled portion229and a second angled portion231. The first angled portion229may extend from the substantially rectilinear portion of the free wall224at an axial angle greater than zero. The second angled portion231may extend from the first angled portion229at an axial angle greater than zero. In this way, the free end226of the free wall224may be positioned radially outer from the substantially rectilinear portion of the free wall224. InFIG.2, the free end226may be positioned adjacent a radially inner surface of the connecting wall228such that a gap233is formed between the free end226and the radially inner surface of the connecting wall228. The gap233may include any size, as desired, for controlling an amount of cooling air that may be directed through the gap233, as detailed further below.

The looped section220may include one or more fastener holes240extending therethrough to receive the one or more fastening mechanisms212. In this way, the outer annular dome124and the outer cowl130may be fastened to the outer liner assembly102at the looped section220. One such fastener hole240is shown inFIG.2. The fastener hole240may include a first fastener hole extending through the connecting wall228and a second fastener hole extending through the free wall224. The one or more fastening mechanisms212may be inserted through the first fastener hole, into the cavity230, and through the second fastener hole. The one or more fastening mechanisms212may be inserted through respective fastener holes of the outer annular dome124and the outer cowl130to fasten or otherwise to secure the outer annular dome124and the outer cowl130to the liner202at the looped section220. In this way, the one or more fastening mechanisms212may be situated or otherwise disposed within the cavity230when the outer annular dome124and the outer cowl130are mounted to the liner202. For example, the looped section220may be considered to loop around the one or more fastening mechanisms212.

One or more seals242may seal the fastener holes240to prevent and/or to control air flow through the fastener holes240. For example, the one or more seals242may include one or more U-shaped or curved washers (shown inFIG.2) to seal the fastener holes240. The one or more seals242may include any type of known seal for sealing the fastener holes240. Two such seals242are shown inFIG.2. For example, a first seal242is positioned between the fastening mechanism212and the free wall224to prevent air leakage through an area around the fastening mechanism212. A second seal242is positioned between the fastening mechanism212and the outer cowl130to further prevent air leakage through the area around the fastening mechanism212. In some examples, the one or more seals242may include a size and/or a shape substantially similar to a size and/or a shape of the fastener hole240(e.g., the fastener hole through the connecting wall228). In this way, the one or more seals242may span a diameter of the fastener hole240to seal the fastener hole240.

When the liner202includes the looped section220of the present disclosure, the first distance105(FIG.1) may be defined by the connecting wall228and the outer combustor casing106. The looped section220may decrease the first distance105due to the looped section220extending radially outward from the outer cowl130. Thus, a diameter of the outer cowl130may be sized to maintain the size of the first distance105, accordingly. For example, the first distance105may be substantially equal between embodiments without the looped section220and in embodiments with the looped section220. In this way, the first distance105may be maintained while the liner202includes the benefit of the present disclosure. A diameter of the inner cowl128(FIG.1) may likewise be sized to maintain the second distance107(FIG.1), accordingly.

The looped section220may include one or more first cooling holes250for providing cooling air into the cavity230. For example, the one or more first cooling holes250may be located on the first bend222a. The one or more first cooling holes250may include one or more metering holes such that the cooling air enters the one or more first cooling holes250and exits the one or more first cooling holes250as a jet (e.g., velocity of the cooling air is increased as the cooling air passes through the one or more first cooling holes250). The one or more first cooling holes250may include a plurality of discrete cooling holes (e.g., multiple separate cooling holes positioned at various circumferential positions on the looped section220). In some examples, the one or more first cooling holes250may include an annular opening that spans around the circumference of the looped section220. The one or more first cooling holes250may include a combination of discrete cooling holes and/or annular openings. The one or more first cooling holes250may include any number of cooling holes, as desired. The one or more first cooling holes250may include any size and/or shape, and may be positioned at any angle to provide cooling air into the cavity230.

The looped section220may also include one or more second cooling holes260for providing the cooling air from the cavity230to one or more components of the combustion section26, as detailed further below. The one or more second cooling holes260may be located on the distal bent portion227of the free wall224. For example, the one or more second cooling holes260may extend through the free wall224downstream of the one or more first cooling holes250. The one or more second cooling holes260may be positioned and angled to provide cooling air from the cavity230to the outer annular dome124, the deflector assembly160, the heat shield204, and/or any other component of the combustion section26(FIG.1) adjacent the looped section220. The one or more second cooling holes260may include one or more metering holes such that the cooling air enters the one or more second cooling holes260and exits the one or more second cooling holes260as a jet (e.g., velocity of the cooling air is increased as the cooling air passes through the one or more second cooling holes260). The one or more second cooling holes260may include a plurality of discrete cooling holes (e.g., multiple separate cooling holes positioned at various circumferential positions on the looped section220). In some examples, the one or more second cooling holes260may include an annular opening that spans around the circumference of the looped section220. The one or more second cooling holes260may include a combination of discrete cooling holes and/or annular openings. The one or more second cooling holes260may include any number of cooling holes, as desired. The one or more second cooling holes260may include any size and/or shape, and may be positioned at any angle to provide cooling air from the cavity230to various components of the combustion section26.

In operation, discharge air126(FIG.1) may be directed through the one or more first cooling holes250(as indicated by the arrow through first cooling holes250) to provide cooling air into the cavity230. For example, the discharge air126that is directed along the outer passage flow direction138(FIG.2) may enter the cavity230through the one or more first cooling holes250. The discharge air126may also be directed into the cavity230through the one or more fastener holes240(as indicated by the arrow through fastener holes240), wherein the one or more seals242provide control of the flow of the discharge air126through the one or more fastener holes240. In this way, the one or more fastening mechanisms212may be cooled. The cooling air in the cavity230may then be directed through the one or more second cooling holes260(as indicated by the arrows through the second cooling holes260). The one or more second cooling holes260may include cooling holes to direct the cooling air onto a downstream surface (e.g., a hot side) of the deflector assembly160to cool the deflector assembly160. For example, the cooling air may impinge on the deflector assembly160at specific locations around the deflector assembly160(e.g., at the corners of the panels of the deflector assembly160) to prevent hot gas ingestion and to cool the deflector assembly160. The one or more second cooling holes260may also include cooling holes to direct the cooling air into the space208and may film cool the one or more panels206of the heat shield204.

The cooling air in the cavity230may also be directed through the gap233into the space208(as indicated by the arrow through the gap233). The cooling air directed through the gap233may provide film cooling on the radially inner surface of the liner202(e.g., on the axially angled portion203). The one or more second cooling holes260and the gap233may be metered to further increase a velocity of the cooling air from an upstream side to a downstream side of the one or more second cooling holes260and the gap233, respectively. The direction and/or the amount of cooling air through the first cooling holes250, the second cooling holes260, and/or the gap233may be sized, shaped, and angled to direct the cooling air in various directions, as necessary.

FIG.3is a schematic partial cross-sectional view of another embodiment of the forward end103of the outer liner assembly102. The embodiment ofFIG.3includes many of the same or similar components and functionality as the embodiment shown inFIG.2. The same reference numeral is used for the same or similar components in these two embodiments, and a detailed description of these components and functionality is omitted here. Some reference numerals have been removed for clarity.

InFIG.3, the one or more second bends222bmay include one second bend222b. For example, the distal bent portion227may include only a first angled portion229. InFIG.3, the first angled portion229may extend from the substantially rectilinear portion of the free wall224at an axial angle of about ninety degrees. The first angled portion229may extend from the substantially rectilinear portion of the free wall224at any angle greater than zero, as desired. In this way, the free end226of the free wall224may extend substantially radially. The gap233between the free end226and the radially inner surface of the connecting wall228may be larger than in the embodiment ofFIG.2. The free end226may extend toward the radially inner surface of the connecting wall228at any radial distance such that the gap233may include any size, as desired, for controlling an amount of cooling air that may be directed through the gap233.

FIG.4is a schematic partial cross-sectional view of another embodiment of the forward end103of the outer liner assembly102. The embodiment ofFIG.4includes many of the same or similar components and functionality as the embodiment shown inFIG.2. The same reference numeral is used for the same or similar components in these two embodiments, and a detailed description of these components and functionality is omitted here. Some reference numerals have been removed for clarity.

InFIG.4, the first angled portion229includes less of an angle than in the embodiment ofFIG.2. The second angled portion231extends from the first angled portion229at less of an angle than the second angled portion231of the embodiment inFIG.2. In this way, the free end226of the free wall224extends axially towards a proximal end of the heat shield204and a gap235is formed between the free end226and the proximal end of the heat shield204.

As shown inFIG.4, the looped section220may include one or more third cooling holes270for providing cooling air into the cavity230. The one or more third cooling holes270may be located on the connecting wall228downstream of the one or more fastener holes240. For example, the one or more third cooling holes270may extend substantially radially through the connecting wall228. In some examples, the one or more third cooling holes270may be located upstream of the one or more fastener holes240. The one or more third cooling holes270may include one or more metering holes such that the cooling air enters the one or more third cooling holes270and exits the one or more third cooling holes270as a jet (e.g., velocity of the cooling air is increased as the cooling air passes through the one or more third cooling holes270). The one or more third cooling holes270may include a plurality of discrete cooling holes (e.g., multiple separate cooling holes positioned at various circumferential positions on the looped section220). In some examples, the one or more third cooling holes270may include an annular opening that spans around the circumference of the looped section220. The one or more third cooling holes270may include any number of cooling holes, as desired. The one or more third cooling holes270may include a combination of discrete cooling holes and/or annular openings. The one or more third cooling holes270may include any size and/or shape, and may be positioned at any angle to provide cooling air into the cavity230.

In operation, in addition to the discharge air126(FIG.1) being directed through the one or more first cooling holes250, the discharge air126may also be directed into the cavity230through the one or more third cooling holes270(as indicated by the arrow through the third cooling holes270). The cooling air in the cavity230may then be directed through the one or more second cooling holes260(as indicated by the arrow through the second cooling holes260). The cooling air through the second cooling holes260may direct the cooling air onto a downstream surface (e.g., a hot side) of the deflector assembly160to cool the deflector assembly160. For example, the cooling air may impinge on the deflector assembly160at specific locations around the deflector assembly160(e.g., at the corners of the panels of the deflector assembly160) to prevent hot gas ingestion and to cool the deflector assembly160.

The cooling air in the cavity230may also be directed through the gap235toward a hot side of the heat shield204(as indicated by the arrow through the gap235). For example, the cooling air directed through the gap235may provide film cooling on the radially inner surface of the one or more panels206. The direction and/or the amount of cooling air through the first cooling holes250, the second cooling holes260, and/or the gap235may be sized, shaped, and/or angled to direct the cooling air in various directions, as necessary.

FIG.5is a schematic partial cross-sectional view of another embodiment of the forward end103of the outer liner assembly102. The embodiment ofFIG.5includes many of the same or similar components and functionality as in the embodiment shown inFIG.2. The same reference numeral is used for the same or similar components in these two embodiments, and a detailed description of these components and functionality is omitted here. Some reference numerals have been removed for clarity.

InFIG.5, a looped section520may be positioned downstream of the one or more fastening mechanisms212and may include a different shape than the looped section220of the embodiments shown inFIGS.2to4. The looped section520ofFIG.5may include one or more bends522positioned axially downstream of the free wall224. For example, the free end226of the free wall224may be positioned upstream of the one or more fastening mechanisms212. The free wall224may extend downstream from the free end226and the looped section520may begin at an axial position downstream of the one or more fastening mechanisms212. In this way, the looped section520is not considered to loop around the one or more fastening mechanisms212as in the embodiments of the looped section220of the embodiments ofFIGS.2to4.

The one or more bends522may include a first bend522aat a downstream end of the free wall224. The first bend522amay include a bend angle greater than zero such that a first connecting wall228aextends from the free wall224at the first bend522a. The first connecting wall228amay extend radially outward from the free wall224and may be substantially radial (e.g., the bend angle of the first bend522amay be approximately ninety degrees). The first bend522amay include a first diameter. The size (e.g., the first diameter) and/or the shape of the first bend522amay include any size and/or shape, as desired, for forming a portion of the looped section520. The free wall224may extend from the free end226to a first portion of the first bend522a. The first connecting wall228amay extend from a second portion of the first bend522a.

A second bend522bmay be defined at a radially outer end of the first connecting wall228a. The second bend522bmay form an elongated U-shape or an elongate C-shape. In this way, the second bend522bmay form a smoothly curved, arcuate configuration. The second bend522bmay include a second diameter. The size (e.g., the second diameter) and/or the shape of the second bend522bmay include any size and/or shape, as desired, for forming a portion of looped section520. The first connecting wall228amay extend to a first portion of the second bend522band a second connecting wall228bmay extend from a second portion of the second bend522b. In this way, the second bend522bmay be considered to bend one hundred eighty degrees such that the second connecting wall228bis substantially parallel with the first connecting wall228a. Further the first connecting wall228a, the second bend522b, and the second connecting wall228bmay include a shape considered to be an upside-down U-shape.

A third bend522cmay be defined at a radially inner end of the second connecting wall228b. The third bend522cmay form an elongated U-shape or an elongate C-shape. In this way, the third bend522cmay form a smoothly curved arcuate configuration. The third bend522cmay include a third diameter. The size (e.g., the third diameter) and/or the shape of the third bend522cmay include any size and/or shape, as desired, for forming a portion of looped section520. The second connecting wall228bmay extend to a first portion of the third bend522cand a third connecting wall228cmay extend from a second portion of the third bend522c. In this way, the third bend522cmay be considered to bend one hundred eighty degrees such that the third connecting wall228cis substantially parallel with the second connecting wall228b. Further the second connecting wall228b, the third bend522c, and the third connecting wall228cmay include a shape considered to be a U-shape.

The second bend522bmay form a first cavity530aand the third bend522cmay form a second cavity530b. The first cavity530amay include a size and/or a shape defined by a size and/or a shape of the second bend522b, the first connecting wall228a, and the second connecting wall228b. In this way, the first cavity530amay include a first volume. The second cavity530bmay include a size and/or a shape defined by a size and/or a shape of the third bend522c, the second connecting wall228b, and the third connecting wall228c. In this way, the second cavity530bmay include a second volume. The second volume may be substantially similar to the first volume, or may be different (e.g., larger or smaller) than the first volume.

A connecting bend221may be formed between the third connecting wall228cand the axially angled portion203of the liner202. The connecting bend221may direct the shape of the liner202from the axially angled portion203to the third connecting wall228csuch that the third connecting wall228cextends substantially radially (e.g., rectilinear). The connecting bend221may include any size and/or a shape, as desired, for forming a smooth transition between the axially angled portion203and the third connecting wall228c.

The looped section520may include one or more fastener holes240extending therethrough to receive the one or more fastening mechanisms212. For example, the one or more fastener holes240may extend through the free wall224. In this way, the outer annular dome124and the outer cowl130may be fastened to the outer liner assembly102at the looped section220(e.g., at the free wall224). The one or more fastening mechanisms212may also include one or more seals242, as detailed above with respect toFIG.2.

As shown inFIG.5, the looped section520may include one or more first cooling holes250, one or more second cooling holes260, and one or more third cooling holes270. The one or more first cooling holes250may be located upstream of the first connecting wall228a. For example, the one or more first cooling holes250may be located on the first bend522a. One such first cooling hole250is shown inFIG.5. The one or more first cooling holes250may be oriented, sized, shaped, and/or positioned to direct cooling air (e.g., discharge air126) towards a hot side of the deflector assembly160(as indicated by the arrow through the first cooling holes250).

The one or more second cooling holes260may be located downstream of the second bend522b. For example, the one or more second cooling holes260may include cooling holes on the second connecting wall228band may include cooling holes on or adjacent the first portion of the third bend522c. Two such second cooling holes260are shown inFIG.5. The one or more second cooling holes260that are on the second connecting wall228bmay direct cooling air into the first cavity530a(as indicated by the arrows through such one or more second holes260). The one or more second cooling holes260that are on the first portion of the third bend522cmay provide cooling air from the second cavity530b(as indicated by the arrows through such one or more cooling holes260). The one or more second cooling holes260may be oriented, sized, shaped, and/or positioned to direct cooling air (e.g., discharge air126) through the second connecting wall228band towards the deflector assembly160(FIG.1) (as indicated by the arrows through the second cooling holes260).

The one or more third cooling holes270may be located downstream of the second connecting wall228b. For example, the one or more third cooling holes270may include cooling holes on the second portion of the third bend522c. In some examples, the one or more third cooling holes270may include cooling holes on the third connecting wall228c. One such third cooling hole270is shown inFIG.5. The one or more third cooling holes270may be oriented, sized, shaped, and/or positioned to direct cooling air (e.g., discharge air126) from the second cavity530bthrough third bend522cand towards the panels206of the heat shield204to provide cooling air to the heat shield204. The direction of the cooling air through the first cooling holes250and/or the amount of the cooling air through the first cooling holes250, the second cooling holes260, and/or the third cooling holes270may be sized, shaped, and/or angled to direct the cooling air in various directions, as necessary.

FIG.6is a schematic partial cross-sectional view of a forward end103, or an upstream end, of the outer liner assembly102, according to another embodiment of the present disclosure. The embodiment ofFIG.6includes many of the same or similar components and functionality as the embodiment shown inFIG.2. The same reference numeral is used for the same or similar components in these two embodiments, and a detailed description of these components and functionality is omitted here.

InFIG.6, the looped section220is substantially similar to the embodiment of the looped section220inFIG.2, as detailed above. The looped section220ofFIG.6, however, does not include the distal bent portion227(FIG.3) of the free wall224. As shown inFIG.6, the free wall224is substantially rectilinear. The free end226of the free wall224may be substantially axially aligned with the distal end of the outer cowl130. In some examples, the free end226may be positioned axially distal from the distal end of the outer cowl130(e.g., the free end226may extend beyond the distal end of the outer cowl130) or may be positioned axially proximal from the distal end of the outer cowl130(e.g., the free end226may not extend to or beyond the distal end of the outer cowl130).

As further shown inFIG.6, rather than the free wall224including the distal bent portion227(FIG.3), the outer annular dome124may include a bent section627. The bent section627may be located downstream of the free end226of the free wall224. In this way, the bent section627of the outer annular dome124may be located downstream of the cavity230of the looped section220.

The bent section627may include one or more bends622. For example, the one or more bends622may include a first bend622aand a second bend622b. The outer annular dome124may include a free wall624having a free end626defining a proximal end of the outer annular dome124. The free wall624may extend distally from the free end626. The first bend622amay be located at a downstream end, also referred to as a distal end, of the free wall624. The first bend622amay include a bend angle greater than zero degrees such that a first connecting wall628aextends from the free wall624at the first bend622a. The first connecting wall628amay extend radially outward from the free wall624and may be substantially radial (e.g., the bend angle of the first bend622amay be approximately ninety degrees). The first bend622amay include a first diameter. The size (e.g., the first diameter) and/or the shape of the first bend622amay include any size and/or shape, as desired, for forming a portion of the bent section627of the outer annular dome124. The free wall624may extend from the free end626to a first portion of the first bend622a. The first connecting wall628amay extend from a second portion of the first bend622a.

The second bend622bmay be defined at a radially outer end of the first connecting wall628a. The second bend622bmay form an elongated U-shape or an elongated C-shape. In this way, the second bend622bmay form a smoothly curved, arcuate configuration. The second bend622bmay include a second diameter. The size (e.g., the second diameter) and/or the shape of the second bend622bmay include any size and/or shape, as desired, for forming a portion of the bent section627. The first connecting wall628amay extend to a first portion of the second bend622band a second connecting wall628bmay extend from a second portion of the second bend622b. In this way, the second bend622bmay be considered to bend one hundred eighty degrees such that the second connecting wall628bis substantially parallel with the first connecting wall628a. Further the first connecting wall628a, the second bend622b, and the second connecting wall628bmay include a shape considered to be an upside-down U-shape. The second bend622bmay be located radially adjacent a radially inner surface of the connecting wall228of the looped section220. In this way, a radial gap633may be formed between the second bend622band the radially inner surface of the connecting wall228. Further, an axial gap635, also referred to as a cavity, may be formed between the first connecting wall628aand the second connecting wall628b. Although not shown, the second connecting wall628bmay extend radially inward from the second bend622band may define a downstream surface of the outer annular dome124.

The bent section627may include one or more fourth cooling holes650. The one or more fourth cooling holes650may be located on the second connecting wall628b. One such fourth cooling hole650is shown inFIG.6. The one or more fourth cooling holes650may also be located on the second bend622b, as desired. The one or more fourth cooling holes650may be oriented, sized, shaped, and/or positioned to direct cooling air (e.g., discharge air126) towards an upstream side, or a cold side, of the deflector assembly160(as indicated by the arrow through the fourth cooling holes650).

In operation, cooling air (e.g., discharge air126) may enter the cavity230, as detailed above with respect toFIG.2. The cooling air in the cavity230may then be directed through the radial gap633(as indicated by the arrow through the radial gap633). The cooling air through the radial gap633may provide cooling on the liner202, may provide cooling on a hot side of the heat shield204, and/or may be directed to provide cooling on the downstream surface of the deflector assembly160. The cooling air in the cavity230may also be directed through the one or more fourth cooling holes650and towards the upstream surface of the deflector assembly160(as indicated by the arrows through the fourth cooling holes650). For example, the cooling air may be directed between the downstream surface of the outer annular dome124and the upstream surface of the deflector assembly160. The one or more fourth cooling holes650and the radial gap633may be metered to further increase a velocity of the cooling air from an upstream side to a downstream side of the one or more fourth cooling holes650and the radial gap633, respectively. The direction and/or the amount of cooling air through the fourth cooling holes650and/or the radial gap633may be sized, shaped, and angled to direct the cooling air in various directions, as necessary.

FIG.7Ais a schematic cross-sectional view of another embodiment of a forward end103of an outer liner assembly102. The embodiment ofFIG.7Aincludes many of the same or similar components and functionality as those in the embodiment shown inFIG.2. The same reference numeral is used for the same or similar components in these two embodiments, and a detailed description of these components and functionality is omitted here. Further, the embodiment ofFIG.7Ashows both the outer liner assembly102and the inner liner assembly104.

InFIG.7A, a looped section720may be positioned downstream of the one or more fastening mechanisms212and may include a different shape than the looped section220of the embodiments inFIGS.2to4andFIG.6. The looped section720ofFIG.7may be similar to the looped section520ofFIG.5. The looped section720, however, may include one or more upper case omega shapes, as detailed further below.

The looped section720may include one or more bends722positioned axially downstream of the free wall224. For example, the free end226of the free wall224may be positioned upstream of the one or more fastening mechanisms212. The free wall224may extend downstream from the free end226and the looped section720may begin at an axial position downstream of the one or more fastening mechanisms212. In this way, the looped section720is not considered to loop around the one or more fastening mechanisms212as in the embodiments of the looped section220ofFIGS.2to4andFIG.6.

The one or more bends722in the liner202form the looped section720. For example, the liner202may include a unitary length of liner202bent at a first bend722ato form a first general upper-case omega shape and bent at a second bend722bto form a second general upper-case omega shape. In this way, the first bend722aand the second bend722bmay each form a smoothly curved, arcuate configuration. The first bend722amay include a first diameter and the second bend722bmay include a second diameter. The size (e.g., the first diameter and the second diameter) and/or the shape of the first bend722aand the second bend722bmay include any size and/or shape, as desired, for forming the looped section220at the forward end103of the liner202.

The first bend722amay include a first portion723and a second portion725. The first portion723may be connected to the downstream end of the free wall224. The first portion723may extend from the free wall224at an axial angle less than zero degrees such that the first portion723may extend radially inward from the free wall224. The first bend722amay thus be oriented such that the upper-case omega shape is considered upside down. For example, the first bend722amay extend radially inward from the free wall224. The second portion725may be connected to the second bend722b.

The second bend722bmay include a third portion727and a fourth portion729. The third portion727may be connected to the second portion725of the first bend722asuch that the second bend722bis connected to the first bend722a. In this way, the second bend722band the first bend722amay be considered to share a wall or otherwise may blend into each other. The fourth portion729may be connected to the axially extending portion203. In this way, a unitary structure of the liner202may be formed between the free wall224, the first bend722a, the second bend722b, and the downstream portions of the liner202. The second bend722bmay extend axially outward from the axially angled portion203of the liner202. Thus, the second bend722bmay be considered to be a generally right-side-up upper-case omega shape. The first bend722aand the second bend722bmay be angled such that a first central longitudinal axis of the first bend722aand a second central longitudinal axis of the second bend722beach includes an axial component and a radial component.

The first bend722amay define a first cavity730aand the second bend722bmay define a second cavity730b. A size and/or a shape (e.g., a volume) of the first cavity730amay be defined by the size and/or the shape of the first bend722a. A size and/or a shape (e.g., a volume) of the second cavity730bmay be defined by the size and/or the shape of the second bend722b. The first bend722aand the second bend722bmay be oriented such that the first cavity730ais downstream of the second cavity730b. The first bend722amay include a first gap733adefined therein and the second bend722bmay define a second gap733bdefined therein. The first gap733amay enable cooling air into the first cavity730aand the second gap733bmay enable cooling air to exit the second cavity730b, as detailed further below.

InFIG.7A, one or more fastener holes240may extend through the free wall224to receive the one or more fastening mechanisms212. In this way, the outer annular dome124and the outer cowl130may be fastened to the outer liner assembly102at the free wall224. The one or more fastening mechanisms212may also include one or more seals242(not shown inFIG.7A), as detailed above with respect toFIG.2.

As shown inFIG.7A, the looped section720may include one or more first cooling holes750and one or more second cooling holes760. One such first cooling hole750and two such second cooling holes760are shown inFIG.7A. The one or more first cooling holes750are located on the second bend730band may be oriented, sized, shaped, and/or positioned to direct cooling air (e.g., discharge air126) into the second cavity730b.

The one or more second cooling holes760may be located on the first bend722a. For example, the one or more second cooling holes760may include cooling holes to direct cooling air on the downstream surface of the deflector assembly160and may include cooling holes to direct cooling air towards the heat shield204, as detailed below. The one or more second cooling holes760may be oriented, sized, shaped, and/or positioned to direct cooling air (e.g., discharge air126) through the first bend722aand towards the deflector assembly160(as indicated by the arrows through the second cooling holes260) and/or towards the heat shield204, as necessary.

In operation, cooling air (e.g., discharge air126) may be directed through the one or more first cooling holes750and into the second cavity730b. The cooling air may then be directed through the second gap733btowards the space208and onto the radially inner surface of the liner202and/or the radially outer surface of the heat shield204. The cooling air may also be directed through first gap733ainto the first cavity730aand towards the first bend722a. The cooling air may then be directed through the one or more second cooling holes760and onto the deflector assembly160and/or the hot side of the heat shield204. In this way, the looped section720may cool certain components of the outer liner assembly102and/or the inner liner assembly104. The one or more first cooling holes750, the one or more second cooling holes760, the first gap733a, and the second gap733bmay be metered to further increase a velocity of the cooling air from an upstream side to a downstream side of the one or more first cooling holes750, the one or more second cooling holes760, the first gap733a, and the second gap733b, respectively. The one or more first cooling holes750, the one or more second cooling holes760, the first gap733a, and the second gap733bmay be sized, shaped, and angled to direct the cooling air in various directions, as necessary.

FIG.7Aalso shows various sizes and shapes of the looped section720. For example, the second bend722bmay include a first alternate shape721aand a size shown in a first set of dashed lines at the inner liner assembly104. The second bend722bmay also include a second alternate shape721band a size shown in a second set of dashed lines at the inner liner assembly104. Thus, the second bend722bmay include various sizes and/or shapes to tune to a specific vibrational frequency, as detailed further below. Although not shown, the first alternate shape721aand the second alternate shape721bmay be annular such that the outer liner assembly102also includes such shapes. The first bend722amay also include various sizes and/or shapes, accordingly. In this way, the looped section720may include any size and/or shape, as necessary, for acoustic dampening, as detailed further below.

FIG.7Bis a cross-sectional front view of the second gap733btaken along line A-A inFIG.7A. As shown inFIG.7B, the liner202may include one or more acoustic feed holes770positioned circumferentially around an area of the second gap733b. The one or more acoustic feed holes770may be positioned around the liner202and/or may include any size and/or shape, as desired, to tune to a particular frequency such as to avoid, to reduce, or to prevent vibrations in the liner202. The acoustic feed holes770may be in addition to the cooling holes detailed above. In some examples, the cooling holes may act as acoustic feed holes. In operation, air (e.g., discharge air126) may pass through the one or more acoustic feed holes770and dampen any vibrational frequency in the liner202, as necessary. For example, the acoustic feed holes770act as a Helmholtz resonator such that a volume of air in the acoustic feed holes770vibrates at the tuned frequency of the acoustic feed holes770. The one or more acoustic feed holes770may also provide the air for cooling purposes as well. The acoustic feed holes770may be used in any of the embodiments ofFIGS.2to7A, as detailed above.

The looped sections220,520, and720detailed above with respect toFIGS.2to7Bmay be looped and/or bent in a way to provide a compliant joint on the liner202at the respective looped sections220,520, and720. The compliant joint may provide a kinematic degree of freedom between connected parts of a monolithic structure. For example, the compliant joint of the looped sections220,520, and720may provide a kinematic degree of freedom between a portion of the liner202upstream of the looped sections220,520, and720and a portion of the liner202downstream of the looped sections220,520,720. Such a compliant joint may provide vibrational dampening such that acoustic oscillations, vibrations, and other mechanical stresses in an area of the looped sections220,520, and720is reduced. In this way, the looped sections220,520, and720may reduce or prevent the acoustic oscillations, the vibrations, and/or the mechanical stress (e.g., from the fastening mechanisms212) from propagating through the liner202downstream of the respective looped sections220,520, and720. Thus, the looped sections220,520, and720may help to increase an overall lifecycle of the liner202.

The looped sections220,520, and720of the embodiments shown inFIGS.2to7Bmay also help to control cooling and placement of cooling holes, as detailed above. In this way, cooling air may be provided to the deflector assembly160, the outer annular dome124, the inner annular dome122, the liner202downstream of the looped sections220,520, and720, and/or the heat shield204. In this way, the cooling arrangement provided by the looped sections220,520, and720may improve durability and increase a lifecycle of the liner202, the outer annular dome124, the inner annular dome122, and the deflector assembly160.

The looped sections220,520, and720may also include a size and/or a shape for further providing acoustic dampening. For example, the volume of the cavities230,730a, and730b, the length of the free wall224, and/or the length of the connecting wall228may be sized and/or shaped to tune the looped sections220,520, and720to a specific acoustic frequency, as desired. In this way, the size and/or the shape of the looped sections220,520, and720(in combination with the cooling holes and acoustic feed holes) may further prevent vibrations and mechanical stress from propagated through downstream portions of the liner202.

FIG.8Ais a schematic partial cross-sectional view of a forward end103, or an upstream end, of an outer liner assembly102, according to another embodiment. The embodiment ofFIG.8Aincludes many of the same or similar components and functionality as the embodiment shown inFIG.2. The same reference numeral is used for the same or similar components in these two embodiments, and a detailed description of these components and functionality is omitted here. WhileFIG.8Adoes not show a looped section at the forward end103of the outer liner assembly102, the forward end103ofFIG.8Amay, of course, include a looped section, as detailed above.FIG.8Bis a cross-sectional front view of a downstream surface802of a panel804of the deflector assembly160, taken at line8-8inFIG.8A, according to aspects of the present disclosure.FIG.8Cis a cross-sectional front view of another embodiment of a downstream surface802of a panel804of the deflector assembly160.

The deflector assembly160may include one or more panels804that together define the deflector assembly160(one such panel804is shown inFIGS.8B and8C). The panel804may include one or more fastening mechanisms806(e.g., bolts, nuts, screws, brazing, welding, or the like) arranged at or adjacent various corners of the panel804. The fastening mechanisms806may fasten each panel804to the annular dome assembly120such that the deflector assembly160may be fastened to the annular dome assembly120. The outer liner assembly102may include one or more first cooling holes810and the inner liner assembly104may include one or more second cooling holes812.

The one or more first cooling holes810may extend axially through the outer liner assembly102and the one or more second cooling holes812may extend axially through the inner liner assembly104. In this way, cooling air may be provided to an area around the one or more fastening mechanisms806. In operation, cooling air (e.g., discharge air126) may flow through the one or more first cooling holes810as indicated by the arrows through the one or more first cooling holes810. The cooling air may also be directed through the one or more second cooling holes812as indicated by the arrows through the one or more second cooling holes812. InFIG.8B, the cooling may be directed towards the one or more fastening mechanisms806in a radial direction. InFIG.8C, the one or more first cooling holes810may be angled with respect to the radial direction such that the cooling air is directed tangentially on the one or more fastening mechanisms806. Although not shown, the one or more second cooling holes812may also be angled with respect to the radial direction to provide cooling air through the one or more second cooling holes812tangentially to the one or more fastening mechanisms806. The embodiments ofFIGS.8A to8Cmay be combined and utilized for the cooling holes in the embodiments ofFIGS.2to7B.

The embodiments of the present disclosure disclosed herein provide for an improved liner assembly for the combustor to improve durability and a lifecycle of the liner assembly compared to liner assemblies without the benefit of the present disclosure. For example, the compliant joint provided by the looped section (e.g., via the one or more bends) may help to avoid, to reduce, or to prevent vibrations and/or to avoid, to reduce, or to prevent other mechanical stresses from propagating downstream of the looped section. The looped section provides an air cavity that acts as an acoustic damper to further dampen vibrations and mechanical stress, and that can be tuned to a desired frequency. Thus, the looped section may improve durability of the liner assembly and increase a lifecycle of the liner assembly as compared to liner assemblies without the benefit of the present disclosure.

Further aspects of the present disclosure are provided by the subject matter of the following clauses.

A liner assembly for a combustor. The liner assembly includes a liner defining a combustion chamber of the combustor. The liner includes a looped section at a forward end of the liner. The looped section includes one or more bends such that the looped section forms a compliant joint and vibrations are dampened through the liner downstream of the looped section.

The liner assembly of the preceding clause, where the looped section defines one or more cavities.

The liner assembly of any preceding clause, the one or more cavities being sized to dampen acoustic oscillations.

The liner assembly of any preceding clause, further including one or more fastening mechanisms to attach one or more cowls and an annular dome assembly of the combustor to the liner assembly. The one or more cavities dampen acoustic oscillations downstream of the one or more fastening mechanisms.

The liner assembly of any preceding clause, the looped section including a generally C-shaped bend.

The liner assembly of any preceding clause, the looped section including one or more first cooling holes for directing cooling air into the one or more cavities.

The liner assembly of any preceding clause, the looped section including one or more second cooling holes for providing cooling air from the one or more cavities.

The liner assembly of any preceding clause, the looped section including two or more bends defining two or more cavities.

The liner assembly of any preceding clause, the two or more bends each including a generally U-shaped bend.

The liner assembly of any preceding clause, the two or more bends each including a generally Omega-shaped bend.

The liner assembly of any preceding clause, the looped section being defined by a free wall and a connecting wall.

The liner assembly of any preceding clause, the one or more cavities being defined between the free wall and the connecting wall.

The liner assembly of any preceding clause, the connecting wall being radially outward from the free wall.

The liner assembly of any preceding clause, the connecting wall being connected to an axially angled portion of the liner downstream of the looped section.

The liner assembly of any preceding clause, the free wall including a distal bent portion that includes one or more angled portions.

The liner assembly of any preceding clause, a gap being defined by a distal end of the free wall and a radially inner surface of the connecting wall, cooling air being directed through the gap.

The liner assembly of any preceding clause, a gap being defined by a distal end of the free wall and a proximal end of a heat shield of the liner assembly.

The liner assembly of any preceding clause, the one or more fastening mechanisms being disposed within the one or more cavities.

The liner assembly of any preceding clause, further including one or more seals to seal one or more fastener holes in the looped section.

The liner assembly of any preceding clause, the looped section including one or more acoustic feed holes.

The liner assembly of any preceding clause, further including one or more first cooling holes in the liner to direct cooling air radially through the liner to the one or more fastening mechanisms.

The liner assembly of any preceding clause, the one or more first cooling holes in the liner being angled with respect to a radial direction such that the one or more first cooling holes in the liner direct cooling tangentially to the one or more fastening mechanisms.

A combustor assembly for a combustion section of a gas turbine engine. The combustor assembly includes one or more cowls, an annular dome assembly, and a liner assembly having a liner. The one or more cowls and the annular dome assembly are attached to the liner assembly by one or more fastening mechanisms. The liner includes a looped section at a forward end of the liner. The looped section includes one or more bends such that the looped section forms a compliant joint and vibrations are dampened through the liner downstream of the looped section.

The combustor assembly of the preceding clause, the looped section defining one or more cavities.

The combustor assembly of any preceding clause, the one or more cavities being sized to dampen acoustic oscillations.

The combustor assembly of any preceding clause, the one or more fastening mechanisms attaching the one or more cowls and the annular dome assembly to the liner assembly. The one or more cavities dampen acoustic oscillations downstream of the one or more fastening mechanisms

The combustor assembly of any preceding clause, the looped section including a generally C-shaped bend.

The combustor assembly of any preceding clause, the looped section including one or more first cooling holes for directing cooling air into the one or more cavities.

The combustor assembly of any preceding clause, the looped section including one or more second cooling holes downstream of the one or more first cooling holes for providing cooling air from the one or more cavities to downstream portions of the liner and/or to portions of the annular dome assembly.

The combustor assembly of any preceding clause, the looped section including two or more bends defining two or more cavities.

The combustor assembly of any preceding clause, the two or more bends each including a generally U-shaped bend.

The combustor assembly of any preceding clause, the two or more bends each including a generally Omega-shaped bend.

The combustor assembly of any preceding clause, the looped section being defined by a free wall and a connecting wall.

The combustor assembly of any preceding clause, the one or more cavities being defined between the free wall and the connecting wall.

The combustor assembly of any preceding clause, the connecting wall being radially outward from the free wall.

The combustor assembly of any preceding clause, the connecting wall being connected to an axially angled portion of the liner downstream of the looped section.

The combustor assembly of any preceding clause, the free wall including a distal bent portion that includes one or more angled portions.

The combustor assembly of any preceding clause, a gap being defined by a distal end of the free wall and a radially inner surface of the connecting wall, cooling air being directed through the gap.

The combustor assembly of any preceding clause, a gap being defined by a distal end of the free wall and a proximal end of a heat shield of the liner assembly.

The combustor assembly of any preceding clause, the one or more fastening mechanisms being disposed within the one or more cavities.

The combustor assembly of any preceding clause, further including one or more seals to seal one or more fastener holes in the looped section.

The combustor assembly of any preceding clause, the annular dome assembly including a bent section located downstream of the looped section.

The combustor assembly of any preceding clause, the looped section including one or more acoustic feed holes.

The combustor assembly of any preceding clause, further including one or more first cooling holes in the liner to direct cooling air radially through the liner to the one or more fastening mechanisms.

The combustor assembly of any preceding clause, the one or more first cooling holes in the liner being angled with respect to a radial direction such that the one or more first cooling holes in the liner direct cooling tangentially to the one or more fastening mechanisms.

Although the foregoing description is directed to the preferred embodiments, other variations and modifications will be apparent to those skilled in the art, and may be made without departing from the spirit or scope of the disclosure Moreover, features described in connection with one embodiment may be used in conjunction with other embodiments, even if not explicitly stated above.