Patent Description:
Gas turbine engines may be employed to power various devices. For example, a gas turbine engine may be employed to power a mobile platform, such as an aircraft. In a gas turbine engine, air is compressed in a compressor, and mixed with fuel and ignited in a combustor to generate hot combustion gases, which flow downstream into a turbine section for energy extraction. Due to the high temperatures in many gas turbine engine applications, it is desirable to regulate the operating temperature of certain engine components, particularly those within the mainstream hot gas flow path in order to prevent overheating. As such, it is desirable to cool the combustor components, to prevent or reduce adverse impact and extend useful life. In certain examples, the combustor may include effusion cooling holes to assist in cooling the combustor. Certain effusion cooling holes include a complex geometry, which is not capable of being machined or cast into the combustor.

Accordingly, it is desirable to provide a combustor a method for manufacturing the combustor with the effusion cooling holes to provide improved cooling for the combustor. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. A combustor according to the prior art is known from <CIT>.

According to various embodiments, provided is a combustor for a gas turbine engine. The combustor includes an outer liner having a first end and a second end opposite the first end. The first end is interconnected to the second end by an outer liner wall composed of a plurality of outer wall segments. The combustor includes an inner liner having a first inner end and a second inner end opposite the first inner end. The second inner end is coupled to the second end of the outer liner, and the first inner end interconnected to the second inner end by an inner liner wall composed of a plurality of inner wall segments. Each of the outer liner wall and the inner liner wall cooperate to define a combustion chamber.

The first wall segment of the plurality of outer wall segments is at the first end of the outer liner. At least one of the outer liner wall and the inner liner wall has a double wall, with an effusion cooling system defined between the double wall. The fourth angle is different than a fifth angle defined between the fourth wall segment and a fifth wall segment of the plurality of outer wall segments. The first wall segment, the second wall segment, the third wall segment, the fourth wall segment and the fifth wall segment are each integrally formed. The combustor includes a sixth wall segment, and the sixth wall segment cooperates with the inner liner to define a passageway to an outlet of the combustor.

The plurality of inner wall segments includes a first inner wall segment and a second inner wall segment, and the second inner wall segment extends at a tenth angle relative to the first inner wall segment. The plurality of inner wall segments includes a third inner wall segment that extends at an eleventh angle relative to the second inner wall segment, and the eleventh angle is different than the tenth angle. The plurality of inner wall segments includes a fourth inner wall segment that extends at a twelfth angle relative to the third inner wall segment, and the twelfth angle is different than the tenth angle. The plurality of inner wall segments includes a fifth inner wall segment that extends at a thirteenth angle relative to the third inner wall segment, and the thirteenth angle is different than the twelfth angle. The third wall segment defines at least one fuel injector hole.

Also provided according to various embodiments is a method of manufacturing a combustor for a gas turbine engine. The method includes forming an outer liner having a first end, a second end opposite the first end and an outer liner wall interconnecting the first end and the second end. The outer liner wall includes a plurality of wall segments. The method includes substantially concurrently with the forming of the outer liner, forming an inner liner nested within the outer liner wall, the inner liner having a first inner end and a second inner end opposite the first inner end. The method includes coupling the second inner end of the inner liner to the second end of the outer liner to define a combustion chamber.

The method includes additively manufacturing the outer liner and the inner liner and the longitudinal axis of the combustor is coaxial with a build direction of the combustor during the additive manufacturing. The method includes forming an inner liner wall that interconnects the first inner end and the second inner end, and the inner liner wall includes a plurality of inner wall segments.

The method includes welding the second inner end of the inner liner to the second end of the outer liner. The method includes forming the outer liner with a double wall and an effusion cooling system defined within the double wall. The method includes forming an additional wall segment and coupling the additional wall segment to the first wall segment of the outer liner.

In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any type of combustor, and that the example of a combustor for a gas turbine engine is merely one exemplary embodiment according to the present disclosure. In addition, while combustor is described herein as being used with a gas turbine engine onboard a mobile platform, such as a bus, motorcycle, train, motor vehicle, marine vessel, aircraft, rotorcraft and the like, the various teachings of the present disclosure can be used with a gas turbine engine on a stationary platform. Further, it should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the present disclosure. In addition, while the figures shown herein depict an example with certain arrangements of elements, additional intervening elements, devices, features, or components may be present in an actual embodiment. It should also be understood that the drawings are merely illustrative and may not be drawn to scale. The combustor and the method according to the invention are defined in respectively claim <NUM> and claim <NUM>.

As used herein, the term "axial" refers to a direction that is generally parallel to or coincident with an axis of rotation, axis of symmetry, or centerline of a component or components. For example, in a cylinder or disc with a centerline and generally circular ends or opposing faces, the "axial" direction may refer to the direction that generally extends in parallel to the centerline between the opposite ends or faces. In certain instances, the term "axial" may be utilized with respect to components that are not cylindrical (or otherwise radially symmetric). For example, the "axial" direction for a rectangular housing containing a rotating shaft may be viewed as a direction that is generally parallel to or coincident with the rotational axis of the shaft. Furthermore, the term "radially" as used herein may refer to a direction or a relationship of components with respect to a line extending outward from a shared centerline, axis, or similar reference, for example in a plane of a cylinder or disc that is perpendicular to the centerline or axis. In certain instances, components may be viewed as "radially" aligned even though one or both of the components may not be cylindrical (or otherwise radially symmetric). Furthermore, the terms "axial" and "radial" (and any derivatives) may encompass directional relationships that are other than precisely aligned with (e.g., oblique to) the true axial and radial dimensions, provided the relationship is predominately in the respective nominal axial or radial direction. As used herein, the term "transverse" denotes an axis that crosses another axis at an angle such that the axis and the other axis are neither substantially perpendicular nor substantially parallel. Also as used herein, the terms "integrally formed" and "integral" mean one-piece and exclude brazing, fasteners, or the like for maintaining portions thereon in a fixed relationship as a single unit. The term "substantially" indicates within <NUM>% of a given value or position to account for manufacturing tolerances.

With reference to <FIG>, a simplified cross-sectional view of an exemplary gas turbine engine <NUM> is shown with the remaining portion of the gas turbine engine <NUM> being axisymmetric about a longitudinal axis <NUM>, which also comprises an axis of rotation for the gas turbine engine <NUM>. The gas turbine engine <NUM> may be disposed in an engine case <NUM> and may include a fan section <NUM>, a compressor section <NUM>, a combustion section <NUM>, a turbine section <NUM>, and an exhaust section <NUM>. As will be discussed, the combustion section <NUM> includes a combustor <NUM>, which is configured to be additively manufactured without requiring supports. Generally, the structure of the combustor <NUM> enables the combustor <NUM> to be additively manufactured, which enables an effusion cooling system <NUM> (<FIG>) to be defined in the combustor <NUM>, thereby improving a cooling of the combustor <NUM> and increasing a life of the combustor <NUM> while reducing maintenance costs.

With continued reference to <FIG>, the fan section <NUM> may include a fan <NUM>, which draws in and accelerates at least a portion of the air into the compressor section <NUM>. The compressor section <NUM> may include a series of compressors <NUM> that raise the pressure of the air directed from the fan <NUM>. The compressors <NUM> then direct the compressed air into the combustion section <NUM>. In one example, the compressed air may be directed from the compressors <NUM> into a plenum <NUM> surrounding a combustor <NUM> of the combustion section <NUM>. In the combustion section <NUM>, the high pressure air is mixed with fuel and combusted in the combustor <NUM>. The combusted air is then directed into the turbine section <NUM> via a turbine nozzle, for example.

The turbine section <NUM> may include a series of turbines <NUM>, which may be disposed in axial flow series. The combusted air from the combustion section <NUM> expands through and rotates the turbines <NUM> prior to being exhausted through the exhaust section <NUM>. In one embodiment, the turbines <NUM> rotate to drive equipment in the gas turbine engine <NUM> via concentrically disposed shafts or spools. For example, the turbines <NUM> may drive the compressors <NUM> via one or more shafts <NUM>. <FIG> depicts one exemplary configuration, and other embodiments may have alternate arrangements. It should be noted that the embodiments described herein are applicable to both commercial and military gas turbine engines and auxiliary power units. Moreover, as mentioned previously, exemplary embodiments may find beneficial uses in many industries, including aerospace and particularly in high performance aircraft, as well as automotive, marine and power generation.

In this example, the combustor <NUM> is substantially symmetric about the longitudinal axis <NUM>, and has a centerline C that is substantially coaxial with the longitudinal axis <NUM>. The longitudinal axis <NUM> of the gas turbine engine <NUM> also defines a longitudinal axis for the combustor <NUM>. In one example, the combustor <NUM> is a reverse flow combustor. The combustor <NUM> includes an outer liner <NUM> and an inner liner <NUM> that cooperate to define a combustion chamber <NUM>. The outer liner <NUM> defines an outer perimeter or circumference of the combustor <NUM>, while the inner liner <NUM> defines an inner perimeter or circumference of the combustor <NUM>. In one example, the outer liner <NUM> includes a first outer end <NUM>, a second outer end <NUM> opposite the first outer end <NUM>, and an outer liner wall <NUM>. The first outer end <NUM> is fluidly coupled to the turbine section <NUM> to direct the combustive gas flow from the combustor <NUM> to the turbine section <NUM>. The second outer end <NUM> is upstream from the first outer end <NUM> in a direction of working fluid flow through the gas turbine engine <NUM>, and is coupled to the inner liner <NUM> to enclose the combustion chamber <NUM>.

With reference to <FIG>, the outer liner wall <NUM> is shown in greater detail. In one example, the outer liner wall <NUM> is composed of a plurality of outer liner wall segments <NUM>, including: a first wall segment <NUM>, a second wall segment <NUM>, a third wall segment <NUM>, a fourth wall segment <NUM> and a fifth wall segment <NUM>. In one example, a sixth wall segment <NUM> is connected to or formed with the first wall segment <NUM>. Each of the first wall segment <NUM>, the second wall segment <NUM>, the third wall segment <NUM>, the fourth wall segment <NUM>, the fifth wall segment <NUM> and the sixth wall segment <NUM> have a double wall, with an inner wall <NUM> opposite an outer wall <NUM>. As will be discussed, the effusion cooling system <NUM> is defined between the inner wall <NUM> and the outer wall <NUM> and provides cooling for the combustor <NUM>.

The build direction BD extends in an axial direction A, and is perpendicular to a radial direction R. In this example, the build direction BD is substantially parallel to and coaxial with the longitudinal axis <NUM>, and is substantially parallel to and coaxial with the centerline C of the combustor <NUM> (<FIG>). The first wall segment <NUM> is defined at the first outer end <NUM>, and extends for a first distance D1. The first wall segment <NUM> has a first angle α1 relative to the build direction BD. In this example, the first angle α1 is about <NUM> degrees. The first wall segment <NUM> is connected to or integrally formed with the second wall segment <NUM> and is fixedly coupled to the sixth wall segment <NUM>.

The second wall segment <NUM> is connected to or integrally formed with the first wall segment <NUM> and the third wall segment <NUM>. The second wall segment <NUM> extends for a second distance D2, which is different and greater than the first distance D1. The second distance D2 cooperates with the first wall segment <NUM> to define a passageway <NUM> between the outer liner <NUM> and the inner liner <NUM>. The passageway <NUM> directs the combustive gas flow to exit the combustor <NUM> at an outlet <NUM> in fluid communication with the turbine section <NUM>. The second wall segment <NUM> extends at a second angle α2 relative to the build direction BD. In this example, second angle α2 is about <NUM> degrees. The second wall segment <NUM> also extends at a second angle β2 relative to the first wall segment <NUM>. In this example, second angle β2 is about <NUM> degrees.

The third wall segment <NUM> is connected to or integrally formed with the second wall segment <NUM> and the fourth wall segment <NUM>. The third wall segment <NUM> extends for a third distance D3, which is different and less than the second distance D2. The third distance D3 is predetermined to accommodate one or more fuel injector holes <NUM> and one or more quench holes <NUM>. The fuel injector holes <NUM> receive a respective fuel injector (not shown). A single row of quench holes <NUM> is shown in <FIG>, although other arrangements may be provided.

The fuel injector holes <NUM> are defined through the third wall segment <NUM> proximate the fourth wall segment <NUM>. Stated another way, the fuel injector holes <NUM> are defined through the third wall segment <NUM> so as to be axially offset toward the fourth wall segment <NUM>. The fuel injector holes <NUM> are defined so as to be spaced apart about the perimeter or circumference of the combustor <NUM> (<FIG>). The third wall segment <NUM> extends at a third angle α3 relative to the build direction BD. In this example, the third angle α3 is about <NUM> degrees. The third wall segment <NUM> also extends at a third angle β3 relative to the second wall segment <NUM>. In one example, the third angle β3 is about <NUM> degrees.

The fourth wall segment <NUM> is connected to or integrally formed with the third wall segment <NUM> and the fifth wall segment <NUM>. The fourth wall segment <NUM> extends for a fourth distance D4, which is different and less than the second distance D2. The fourth wall segment <NUM> extends at a fourth angle α4 relative to the build direction BD. In this example, the fourth angle α4 is about <NUM> degrees. The fourth wall segment <NUM> also extends at a fourth angle β4 relative to the third wall segment <NUM>. In one example, the fourth angle β4 is about <NUM> degrees.

The fifth wall segment <NUM> is connected to or integrally formed with the fourth wall segment <NUM> and terminates at the second outer end <NUM> of the outer liner <NUM>. The fifth wall segment <NUM> extends for a fifth distance D5, which is different and less than the second distance D2, the third distance D3 and the fourth distance D4. The fifth wall segment <NUM> extends at a fifth angle α5 relative to the build direction BD. In this example, the fifth angle α5 is about <NUM> degrees. The fifth wall segment <NUM> also extends at a fifth angle β5 relative to the fourth wall segment <NUM>. In one example, the fifth angle β5 is about <NUM> degrees.

The sixth wall segment <NUM> is connected to the first wall segment <NUM>. In one example, the sixth wall segment <NUM> is fixedly coupled to the first wall segment <NUM> via welding. The sixth wall segment <NUM> extends includes a first sub-segment 228a that is coupled to the first wall segment <NUM> at the first outer end <NUM> of the outer liner <NUM>, a second sub-segment 228b that extends radially inward from the first outer end <NUM> of the outer liner <NUM> and a third sub-segment 228c. The first sub-segment 228a of the sixth wall segment <NUM> extends for a sixth distance D6, which is different and greater than the first distance D1 and the fifth distance D5. The second sub-segment 228b of the sixth wall segment <NUM> extends for a seventh distance D7, which is different and less than the second distance D2, the third distance D3 and the fourth distance D4. The first sub-segment 228a of the sixth wall segment <NUM> extends at a sixth angle α6 relative to the build direction BD. In this example, the sixth angle α6 is about <NUM> degrees. The first sub-segment 228a also extends at a sixth angle β6 relative to the first wall segment <NUM>. In one example, the sixth angle β6 is about <NUM> degrees.

The second sub-segment 228b of the sixth wall segment <NUM> extends at a seventh angle α7 relative to the build direction BD. In this example, the seventh angle α7 is about <NUM> degrees. The second sub-segment 228b of the sixth wall segment <NUM> also extends at a seventh angle β7 relative to the first sub-segment 228a. In one example, the seventh angle β7 is about <NUM> degrees. The second sub-segment 228b of the sixth wall segment <NUM> cooperates with the inner liner <NUM> to define the passageway <NUM> to direct the combustive gas flow to the turbine section <NUM> (<FIG>).

The third sub-segment 228c may be connected to or integrally formed with the second sub-segment 228b of the sixth wall segment <NUM> and terminates proximate a first inner end <NUM> of the inner liner <NUM>. The third sub-segment 228c cooperates with the inner liner <NUM> to define the outlet <NUM>. In this example, the third sub-segment 228c extends radially inward for an eighth distance D8, and overlaps with a portion of the inner liner <NUM> to define the outlet <NUM>. The eighth distance D8 is different and less than the distances D1-D6. The third sub-segment 228c extends at an eighth angle α8 relative to the build direction BD. In this example, the eighth angle α8 is about <NUM> degrees. The third sub-segment 228c also extends at an eighth angle β8 relative to the second sub-segment 228b of the sixth wall segment <NUM>. In one example, the eighth angle β8 is about <NUM> degrees.

Thus, in this example, the outer liner <NUM> has the first wall segment <NUM> and the first sub-segment 228a that extends along a first axis A1, which is substantially perpendicular to the longitudinal axis <NUM>. The second wall segment <NUM> extends along a second axis A2, which is transverse or oblique to the first axis A1 and the longitudinal axis <NUM>. The third wall segment <NUM> extends along a third axis A3, which is substantially parallel to the longitudinal axis <NUM> and transverse to the second axis A2. The fourth wall segment <NUM> extends along a fourth axis A4, which is transverse or oblique to the second axis A2 and the longitudinal axis <NUM>. The fifth wall segment <NUM> extends along a fifth axis A5, which is substantially parallel to the longitudinal axis <NUM> and transverse to the fourth axis A4. The first sub-segment 228a of the sixth wall segment <NUM> extends along a sixth axis A6, which is substantially parallel to the first axis A1 and substantially perpendicular to the longitudinal axis <NUM>. The second sub-segment 228b of the sixth wall segment <NUM> extends along a seventh axis A7, which is transverse or oblique to the first axis A1 and the longitudinal axis <NUM>. The third sub-segment 228c extends along an eighth axis A8, which is substantially parallel to the longitudinal axis <NUM> and transverse to the sixth axis A6. The axes A2, A4 and A6 are each transverse to the build direction BD, and the axes A3, A5 and A8 are each substantially parallel to the build direction BD. The axes A1 and A6 are each substantially perpendicular to the build direction BD.

The outer liner <NUM> also has the first wall segment <NUM> that extends at the first angle α1 relative to the build direction BD, which is different and greater than the second angle α2 of the second wall segment <NUM>. The second wall segment <NUM> also extends at the second angle β2 relative to the first wall segment <NUM>, which is different and less than the third angle β3 defined between the second wall segment <NUM> and the third wall segment <NUM>. The third wall segment <NUM> extends at the third angle α3 relative to the build direction BD, which is different and greater than the second angle α2 of the second wall segment <NUM> and the fourth angle α4 of the fourth wall segment <NUM>. The third wall segment <NUM> also extends at the fourth angle β4 relative to the fourth wall segment <NUM>, which is different and less than the fifth angle β5 defined between the fourth wall segment <NUM> and the fifth wall segment <NUM>. The second angle β2 is substantially the same or the same as the fourth angle β4. The fourth wall segment <NUM> extends at the fourth angle α4 relative to the build direction BD, which is different and less than the fifth angle α5 of the fifth wall segment <NUM>.

With reference to <FIG>, a detail view of the double wall of the outer liner <NUM> is shown. As discussed, each of the wall segments <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, 228a, 228b and 228c associated with the outer liner wall <NUM> have the double wall, with an inner wall <NUM> opposite an outer wall <NUM> that defines an intervening cavity <NUM> between the inner wall <NUM> and the outer wall <NUM>. As shown in <FIG>, the effusion cooling system <NUM> is defined between the inner wall <NUM> and the outer wall <NUM>. In this example, the effusion cooling system <NUM> includes a plurality of pedestals <NUM>, a plurality of impingement cooling holes <NUM> and a plurality of effusion cooling passages <NUM>. During use, the inner wall <NUM> is exposed to the hot combustive gas flow, and is a hot wall. Conversely, the outer wall <NUM> is exposed to the air that flows into the plenum <NUM> and is a cold wall. As each of the plurality of pedestals <NUM> and the plurality of impingement cooling holes <NUM> are substantially the same as the plurality of pedestals <NUM> and the plurality of impingement cooling holes <NUM> of commonly assigned <CIT>, the relevant portion of which is incorporated herein by reference, the plurality of pedestals <NUM> and the plurality of impingement cooling holes <NUM> will not be discussed in great detail herein.

Briefly, each of the pedestals <NUM> is coupled to or integrally formed with an inner wall surface 230a of the inner wall <NUM> and an outer wall surface 232a of the outer wall <NUM>, and extends through the intervening cavity <NUM>. Each pedestal <NUM> is spaced apart from every other pedestal <NUM>, and each has at least one exterior surface <NUM> facing the intervening cavity <NUM>. That is, the pedestals <NUM> are discrete, and do not share exterior surfaces <NUM>. Each pedestal <NUM> has a principal axis <NUM>, and extends through the intervening cavity <NUM> about its principal axis <NUM>. It will be appreciated that the pedestals <NUM> could be formed to have any one of numerous shapes. In this example, each pedestal <NUM>, when taken along a cross section perpendicular to its principal axis <NUM>, has a circular cross-sectional shape. In other embodiments, however, each pedestal <NUM>, when taken along a cross section perpendicular to its principal axis <NUM>, may have a non-circular cross-sectional shape, such as, for example, elliptical or any one of numerous polygonal shapes. Each of the impingement cooling holes <NUM> extends through the outer wall <NUM> to admit a flow of cooling air into the intervening cavity <NUM>.

Each of the effusion cooling passages <NUM> is associated with a different one of the plurality of pedestals <NUM>, and each has an inlet <NUM> and an outlet <NUM>. The inlet <NUM> of each effusion cooling passage <NUM> is defined proximate the exterior surface <NUM> of its associated pedestal <NUM>, and the outlet <NUM> of each effusion cooling passage <NUM> is defined on the inner wall surface 230a of the inner wall <NUM>. Each effusion cooling passage <NUM> is disposed at a predetermined angle γ relative to the principal axis <NUM> of its associated pedestal <NUM>. The predetermined angle γ may vary, and in one example, is in the range of about <NUM> degrees to about <NUM> degrees. In one example, the principal axis <NUM> is defined at about <NUM> degrees (+/-<NUM> degrees) relative to the inner wall surface 230a and the outer wall surface 232a. In one example, the effusion cooling passage <NUM> is substantially the same as the effusion cooling aperture <NUM> of commonly assigned <CIT>, the relevant portion of which is incorporated herein by reference, the effusion cooling passages <NUM> will not be discussed in great detail herein. In this example, the outlet <NUM> of each of the effusion cooling passages <NUM> includes a recessed portion <NUM>, which is a void area beginning at the inner wall surface 230a of the inner wall <NUM> and extending inwardly toward the outer wall <NUM>. The recessed portion <NUM> includes a surface <NUM>, which surrounds an exit opening <NUM>. The exit opening <NUM> is fluidly coupled via a metering passage <NUM> to the inlet <NUM> to receive the cooling fluid from the intervening cavity <NUM>. The cooling fluid from the intervening cavity <NUM> flows through the metering passage <NUM> exits into the recessed portion <NUM> at the outlet <NUM>. The recessed portion <NUM> further includes an inward surface <NUM>, which extends from the surface <NUM> to the inner wall surface 230a of the inner wall <NUM>, at point P. The recessed portion <NUM> at the outlet <NUM> enables the pressurized air to diffuse and form a film of cooling fluid along the inner wall surface 230a of the inner wall <NUM>.

With reference to <FIG>, the inner wall surface 230a of the outer liner <NUM> is shown. As depicted in <FIG>, the effusion cooling passages <NUM> may be defined so as to be spaced apart about the perimeter or circumference of the outer liner <NUM>. Generally, the outlets <NUM> of the effusion cooling passages <NUM> are arranged to define a film of cooling fluid over the inner wall surface 230a of the outer liner <NUM> to provide cooling for the outer liner <NUM>. It should be noted that the arrangement of the effusion cooling system <NUM> in <FIG>, including the outlets <NUM> of the effusion cooling passages <NUM> is merely an example, and the effusion cooling system <NUM> may be arranged as needed to meet the predetermined cooling requirements for the combustor <NUM>.

With reference to <FIG>, the effusion cooling passages <NUM> also include an overhang portion <NUM> that extends axially over the recessed portion <NUM> beginning from the surface <NUM>. The overhang portion <NUM> includes an outer surface <NUM>, which is an extension of the inner wall surface 230a of the inner wall <NUM> as it extends over the recessed portion <NUM>. The overhang portion <NUM> includes an inner surface 274a, which extends over the recessed portion <NUM>. The overhang portion <NUM> protects the exit opening <NUM> from plugging when a thermal barrier coating is applied to the combustor <NUM>.

With reference back to <FIG>, the inner liner <NUM> includes a first inner end <NUM>, a second inner end <NUM> opposite the first inner end <NUM>, and an inner liner wall <NUM>. The first inner end <NUM> is fluidly coupled to the turbine section <NUM> to direct the combustive gas flow from the combustor <NUM> to the turbine section <NUM> (<FIG>). The second inner end <NUM> is upstream from the first inner end <NUM> in a direction of working fluid flow through the gas turbine engine <NUM>, and is coupled to the outer liner <NUM> to enclose the combustion chamber <NUM>.

With reference to <FIG>, the inner liner wall <NUM> is shown in greater detail. In one example, the inner liner wall <NUM> is composed of a plurality of inner liner wall segments <NUM>, including: a first inner wall segment <NUM>, a second inner wall segment <NUM>, a third inner wall segment <NUM>, a fourth inner wall segment <NUM>, a fifth inner wall segment <NUM> and a sixth inner wall segment <NUM>. Each of the first inner wall segment <NUM>, the second inner wall segment <NUM>, the third inner wall segment <NUM>, the fourth inner wall segment <NUM>, the fifth inner wall segment <NUM> and the sixth inner wall segment <NUM> have a double wall, with the inner wall <NUM> opposite the outer wall <NUM>. In this example, the double wall including the effusion cooling system <NUM> is the same between the outer liner <NUM> and the inner liner <NUM>. Thus, the double wall and the effusion cooling system <NUM> associated with the inner liner <NUM> will not be discussed in detail herein. Briefly, with reference to <FIG>, the inner wall surface 230a of the inner liner <NUM> is shown. The inner wall <NUM> of the inner liner <NUM> is opposite the outer wall <NUM> and defines the intervening cavity <NUM> between the inner wall <NUM> and the outer wall <NUM>. The effusion cooling system <NUM> is defined between the inner wall <NUM> and the outer wall <NUM> of each of the first inner wall segment <NUM>, a second inner wall segment <NUM>, a third inner wall segment <NUM>, a fourth inner wall segment <NUM>, a fifth inner wall segment <NUM> and a sixth inner wall segment <NUM>.

The first inner wall segment <NUM> is defined at the first inner end <NUM>, and extends for a ninth distance D9. The ninth distance D9 is predetermined such that the first inner wall segment <NUM> is spaced a distance apart from the first sub-segment 228a of the sixth wall segment <NUM> of the outer liner <NUM> to form the passageway <NUM>. The first inner wall segment <NUM> extends along the ninth distance D9 so as to be opposite a portion of the second wall segment <NUM> and the third wall segment <NUM>. The first inner wall segment <NUM> has a ninth angle α9 relative to the build direction BD. In this example, the ninth angle α9 is about <NUM> degrees. The first inner wall segment <NUM> is connected to or integrally formed with the second inner wall segment <NUM> and the sixth inner wall segment <NUM>. The first inner wall segment <NUM> includes the one or more quench holes <NUM>. A single row of quench holes <NUM> is shown, although other arrangements may be provided.

The second inner wall segment <NUM> is connected to or integrally formed with the first inner wall segment <NUM> and the third inner wall segment <NUM>. The second inner wall segment <NUM> extends for a tenth distance D10, which is different and less than the ninth distance D9. The second inner wall segment <NUM> extends at a tenth angle α10 relative to the build direction BD. In this example, tenth angle α10 is about <NUM> degrees. The second inner wall segment <NUM> also extends at a tenth angle β10 relative to the first inner wall segment <NUM>. In one example, the tenth angle β10 is about <NUM> degrees.

The third inner wall segment <NUM> is connected to or integrally formed with the second inner wall segment <NUM> and the fourth inner wall segment <NUM>. The third inner wall segment <NUM> extends for an eleventh distance D11, which is different and less than the ninth distance D9 and the tenth distance D10. The eleventh distance D11 cooperates with the tenth distance D10 such that the second inner wall segment <NUM> and the third inner wall segment <NUM> are substantially opposite the fuel injector holes <NUM>. In this example, the second inner wall segment <NUM> and the third inner wall segment <NUM> are substantially opposite a portion of the third wall segment <NUM>. The third inner wall segment <NUM> extends at an eleventh angle α11 relative to the build direction BD. In this example, the eleventh angle α11 is about <NUM> degrees. The third inner wall segment <NUM> also extends at an eleventh angle β11 relative to the second inner wall segment <NUM>. In one example, the eleventh angle β11 is about <NUM> degrees.

The fourth inner wall segment <NUM> is connected to or integrally formed with the third inner wall segment <NUM> and the fifth inner wall segment <NUM>. The fourth inner wall segment <NUM> extends for a twelfth distance D12, which is different and greater than the ninth distance D9 and the tenth distance D10. The twelfth distance D12 is about the same as the fourth distance D4, and the fourth inner wall segment <NUM> is substantially opposite the fourth wall segment <NUM> of the outer liner <NUM>. The fourth inner wall segment <NUM> extends at a twelfth angle α12 relative to the build direction BD. In this example, the twelfth angle α12 is about <NUM> degrees. The fourth wall segment <NUM> also extends at a twelfth angle β12 relative to the third inner wall segment <NUM>. In one example, the twelfth angle β12 is about <NUM> degrees.

The fifth inner wall segment <NUM> is connected to or integrally formed with the fourth inner wall segment <NUM> and terminates at the second inner end <NUM> of the inner liner <NUM>. The fifth inner wall segment <NUM> extends for a thirteenth distance D13, which is different and less than the ninth distance D9, the tenth distance D10, the eleventh distance D11 and the twelfth distance D12. The fifth inner wall segment <NUM> extends at a thirteenth angle α13 relative to the build direction BD. In this example, the thirteenth angle α13 is about <NUM> degrees. The fifth inner wall segment <NUM> also extends at a thirteenth angle β13 relative to the fourth inner wall segment <NUM>. In one example, the thirteenth angle β13 is about <NUM> degrees. The fifth inner wall segment <NUM> extends for about the same length as the fifth wall segment <NUM> of the outer liner <NUM> to facilitate coupling or joining the inner liner <NUM> to the outer liner <NUM> at the respective second ends <NUM>, <NUM>.

The sixth inner wall segment <NUM> is connected to or integrally formed with the first inner wall segment <NUM> and extends radially inward at the first inner end <NUM> of the inner liner <NUM>. The sixth inner wall segment <NUM> extends for a fourteenth distance, which is different and less than the distances D8-D12. The sixth inner wall segment <NUM> extends at a fourteenth angle α14 relative to the build direction BD. In this example, the fourteenth angle α14 is about <NUM> degrees. The sixth inner wall segment <NUM> also extends at a fourteenth angle β14 relative to the first inner wall segment <NUM>. In one example, the fourteenth angle β14 is about <NUM> degrees. The sixth inner wall segment <NUM> cooperates with the first wall segment <NUM> of the outer liner <NUM> to define the passageway <NUM> to direct the combustive gas flow to the turbine section <NUM> (<FIG>).

Thus, in this example, the inner liner <NUM> has the first inner wall segment <NUM> that extends along a ninth axis A9, which is substantially parallel to the longitudinal axis <NUM>. The second inner wall segment <NUM> extends along a tenth axis A10, which is transverse or oblique to the ninth axis A9 and the longitudinal axis <NUM>. The third inner wall segment <NUM> extends along an eleventh axis A11, which is substantially parallel to the longitudinal axis <NUM> and transverse to the tenth axis A10. The fourth inner wall segment <NUM> extends along a twelfth axis A12, which is transverse or oblique to the eleventh axis A11 and the longitudinal axis <NUM>. The fifth inner wall segment <NUM> extends along a thirteenth axis A13, which is substantially parallel to the longitudinal axis <NUM> and transverse to the eleventh axis A11. The sixth inner wall segment <NUM> extends along a fourteenth axis A14, which is substantially perpendicular to the ninth axis A9 and the longitudinal axis <NUM>. The axes A10 and A12 are each transverse to the build direction BD, and the axes A9 and A13 are each substantially parallel to the build direction BD. The fourteenth axis A14 is substantially perpendicular to the build direction BD.

The inner liner <NUM> also has the first inner wall segment <NUM> that extends at the ninth angle α9 relative to the build direction BD, which is different and greater than the tenth angle α10 of the second inner wall segment <NUM>. The second inner wall segment <NUM> also extends at the tenth angle β10 relative to the first inner wall segment <NUM>, which is different and greater than the eleventh angle β11 defined between the second inner wall segment <NUM> and the third inner wall segment <NUM>. The third inner wall segment <NUM> extends at the eleventh angle α11 relative to the build direction BD, which is different and greater than the tenth angle α10 of the second inner wall segment <NUM> and the twelfth angle α12 of the fourth inner wall segment <NUM>. The third inner wall segment <NUM> also extends at the twelfth angle β12 relative to the fourth inner wall segment <NUM>, which is different and less than the thirteenth angle β13 defined between the fourth inner wall segment <NUM> and the fifth inner wall segment <NUM>. The fourth inner wall segment <NUM> extends at the twelfth angle α12 relative to the build direction BD, which is different and less than the thirteenth angle α13 of the fifth inner wall segment <NUM>.

It should be noted that in other applications, the combustor <NUM> may be configured differently for use with a gas turbine engine. For example, with reference to <FIG>, a combustor <NUM> for use with a gas turbine engine <NUM> is shown. As the combustor <NUM> includes features that are substantially similar to or the same as the combustor <NUM> discussed with regard to <FIG>, the same reference numerals will be used to denote the same or similar features. In the example shown in <FIG>, the gas turbine engine <NUM> is illustrated as a single spool engine. It should be noted that the use of a single spool engine is merely exemplary, as any number of spools can be employed. A tie-shaft <NUM> extends along an axis of rotation or longitudinal axis <NUM> of the gas turbine engine <NUM>. In this example, the gas turbine engine <NUM> includes a compressor section <NUM>, a combustion section <NUM>, and a turbine section <NUM>. In certain examples, the compressor section <NUM> includes one or more compressors <NUM>, which are mounted to an upstream or forward end of the tie-shaft <NUM>. The compressors <NUM> are in communication with a compressor section duct <NUM> to receive airflow from an intake section <NUM> of the gas turbine engine <NUM>. The compressors <NUM> pressurize the air in the compressor section duct <NUM>, and the compressor section duct <NUM> is in communication with the combustion section <NUM> to deliver the compressed air to a combustion chamber <NUM> of the combustion section <NUM>. In one example, the compressed air may be directed from the compressors <NUM> into a plenum <NUM> surrounding a combustor <NUM> of the combustion section <NUM>.

The combustion section <NUM> includes the combustor <NUM>, which defines a combustion chamber <NUM>. The compressed air from the compressor section <NUM> is mixed with fuel and ignited to produce combustive gases in the combustor <NUM>. The combustive gases are directed from the combustion chamber <NUM> to the turbine section <NUM>. The turbine section <NUM> includes at least one radial or axial turbine, and in this example, includes a radial turbine <NUM>, which is mounted to an opposing, aft end of the tie-shaft <NUM> as the turbine for the gas turbine engine <NUM>. The turbine section <NUM> also includes a turbine nozzle <NUM>, which is in fluid communication with the combustion section <NUM> to receive combustion gases from the combustion chamber <NUM>. The turbine nozzle <NUM> directs the combustion gases through the radial turbine <NUM>.

The combustion gases drive rotation of the turbine, which in this example incudes the radial turbine <NUM>, and the rotation of the turbine drives further rotation of the tie-shaft <NUM> and the compressors <NUM>. The rotation of the rotating group provides power output, which may be utilized in a variety of different manners, depending upon whether the gas turbine engine <NUM> assumes the form of a turbofan, turboprop, turboshaft, turbojet engine, or an auxiliary power unit, to list but a few examples.

With reference to <FIG>, the combustor <NUM> is substantially symmetric about the longitudinal axis <NUM>, and has a centerline C that is substantially coaxial with the longitudinal axis <NUM>. The longitudinal axis <NUM> also defines a longitudinal axis for the combustor <NUM>. In one example, the combustor <NUM> is a reverse flow combustor. The combustor <NUM> includes an outer liner <NUM> and an inner liner <NUM> that cooperate to define the combustion chamber <NUM>. The outer liner <NUM> defines an outer perimeter or circumference of the combustor <NUM>, while the inner liner <NUM> defines an inner perimeter or circumference of the combustor <NUM>. In one example, the outer liner <NUM> includes a first outer end <NUM>, a second outer end <NUM> opposite the first outer end <NUM>, and an outer liner wall <NUM>. The first outer end <NUM> is fluidly coupled to the turbine section <NUM> to direct the combustive gas flow from the combustor <NUM> to the turbine section <NUM>. The second outer end <NUM> is upstream from the first outer end <NUM> in a direction of working fluid flow through the gas turbine engine <NUM>, and is coupled to the inner liner <NUM> to enclose the combustion chamber <NUM>.

With reference to <FIG>, the outer liner wall <NUM> is shown in greater detail. In one example, the outer liner wall <NUM> is composed of a plurality of outer liner wall segments <NUM>, including: the first wall segment <NUM>, the second wall segment <NUM>, the third wall segment <NUM>, the fourth wall segment <NUM> and the fifth wall segment <NUM>. In one example, a sixth wall segment <NUM> is connected to the first wall segment <NUM>. Each of the first wall segment <NUM>, the second wall segment <NUM>, the third wall segment <NUM>, the fourth wall segment <NUM>, the fifth wall segment <NUM> and the sixth wall segment <NUM> have the double wall, with the inner wall <NUM> opposite the outer wall <NUM>. The effusion cooling system <NUM> is defined between the inner wall <NUM> and the outer wall <NUM> and provides cooling for the combustor <NUM>.

The build direction BD extends in the axial direction A, and is perpendicular to the radial direction R. In this example, the build direction BD is substantially parallel to and coaxial with the longitudinal axis <NUM>, and is substantially parallel to and coaxial with the centerline C of the combustor <NUM> (<FIG>). The first wall segment <NUM> is defined at the first outer end <NUM>, and extends for the first distance D1. The first wall segment <NUM> has the first angle α1 relative to the build direction BD. The first wall segment <NUM> is connected to or integrally formed with the second wall segment <NUM> and is fixedly coupled to the sixth wall segment <NUM>.

The second wall segment <NUM> extends for the second distance D2. The second distance D2 cooperates with the first wall segment <NUM> to define a passageway <NUM> between the outer liner <NUM> and the inner liner <NUM>. The passageway <NUM> directs the combustive gas flow to exit the combustor <NUM> at an outlet <NUM> in fluid communication with the turbine section <NUM>. The second wall segment <NUM> extends at the second angle α2 relative to the build direction BD. The second wall segment <NUM> also extends at the second angle β2 relative to the first wall segment <NUM>.

The third wall segment <NUM> extends for the third distance D3. The third distance D3 is predetermined to accommodate the fuel injector holes <NUM> and the quench holes <NUM>. The fuel injector holes <NUM> are defined through the third wall segment <NUM> so as to be axially offset toward the fourth wall segment <NUM>. The fuel injector holes <NUM> are defined so as to be spaced apart about the perimeter or circumference of the combustor <NUM> (<FIG>). The third wall segment <NUM> extends at the third angle α3 relative to the build direction BD. The third wall segment <NUM> also extends at the third angle β3 relative to the second wall segment <NUM>. The fourth wall segment <NUM> extends for the fourth distance D4. The fourth wall segment <NUM> extends at the fourth angle α4 relative to the build direction BD. The fourth wall segment <NUM> also extends at the fourth angle β4 relative to the third wall segment <NUM>. The fifth wall segment <NUM> terminates at the second outer end <NUM> of the outer liner <NUM>. The fifth wall segment <NUM> extends for the fifth distance D5. The fifth wall segment <NUM> extends at the fifth angle α5 relative to the build direction BD. The fifth wall segment <NUM> also extends at the fifth angle β5 relative to the fourth wall segment <NUM>.

The sixth wall segment <NUM> is connected to the first wall segment <NUM>. In one example, the sixth wall segment <NUM> is fixedly coupled to the first wall segment <NUM> via welding. The sixth wall segment <NUM> extends includes a first sub-segment 528a that is coupled to the first wall segment <NUM> at the first outer end <NUM> of the outer liner <NUM>, a second sub-segment 528b that extends axially outward inward from the first outer end <NUM> of the outer liner <NUM> and a third sub-segment 528c. The first sub-segment 528a of the sixth wall segment <NUM> extends for a distance DT5, which is different and less than the first distance D1 and the fifth distance D5. The second sub-segment 528b of the sixth wall segment <NUM> extends for a seventh distance DT6, which is different and greater than the first distance D1 and the fifth distance D5. The first sub-segment 528a of the sixth wall segment <NUM> extends at a sixth angle αT6 relative to the build direction BD. In this example, the sixth angle αT6 is about <NUM> degrees. The first sub-segment 528a also extends at a sixth angle βT6 relative to the first wall segment <NUM>. In one example, the sixth angle βT6 is about <NUM> degrees.

The second sub-segment 528b of the sixth wall segment <NUM> extends at a seventh angle αT7 relative to the build direction BD. In this example, the seventh angle αT7 is about <NUM> degrees. The second sub-segment 528b of the sixth wall segment <NUM> also extends at a seventh angle βT7 relative to the first sub-segment 528a. In one example, the seventh angle βT7 is about <NUM> degrees. The second sub-segment 528b of the sixth wall segment <NUM> cooperates with the inner liner <NUM> to define the passageway <NUM> to direct the combustive gas flow to the turbine section <NUM> (<FIG>).

The third sub-segment 528c may be connected to or integrally formed with the second sub-segment 528b of the sixth wall segment <NUM>. The third sub-segment 528c cooperates with the inner liner <NUM> to define the outlet <NUM>. In this example, the third sub-segment 528c extends radially outward for an eighth distance DT8, and overlaps with a portion of the inner liner <NUM> to define the outlet <NUM>. The eighth distance DT8 is different and less than the second distance D2, the third distance D3, the fourth distance D4 and the seventh distance DT7. The third sub-segment 528c extends at an eighth angle αT8 relative to the build direction BD. In this example, the eighth angle αT8 is about <NUM> degrees. The third sub-segment 528c also extends at an eighth angle βT8 relative to the second sub-segment 528b of the sixth wall segment <NUM>. In one example, the eighth angle βT8 is about <NUM> degrees.

Thus, in this example, the outer liner <NUM> has the first wall segment <NUM> and the first sub-segment 228a that extends along the first axis A1, which is substantially perpendicular to the longitudinal axis <NUM>. The second wall segment <NUM> extends along the second axis A2, which is transverse or oblique to the first axis A1 and the longitudinal axis <NUM>. The third wall segment <NUM> extends along the third axis A3, which is substantially parallel to the longitudinal axis <NUM> and transverse to the second axis A2. The fourth wall segment <NUM> extends along the fourth axis A4, which is transverse or oblique to the second axis A2 and the longitudinal axis <NUM>. The fifth wall segment <NUM> extends along the fifth axis A5, which is substantially parallel to the longitudinal axis <NUM> and transverse to the fourth axis A4. The first sub-segment 528a of the sixth wall segment <NUM> extends along a sixth axis AT6, which is which is substantially parallel to the first axis A1 and substantially perpendicular to the longitudinal axis <NUM>. The second sub-segment 528b of the sixth wall segment <NUM> extends along a seventh axis AT7, which is substantially perpendicular to the first axis A1 and substantially parallel to the longitudinal axis <NUM>. The third sub-segment 528c extends along an eighth axis AT8, which is substantially parallel to the first axis A1 and substantially perpendicular to the longitudinal axis <NUM>. The axes A2 and A4 are each transverse to the build direction BD, and the axes A3 and AT7 are each substantially parallel to the build direction BD. The axes A1, AT6 and AT8 are each substantially perpendicular to the build direction BD.

The outer liner <NUM> also has the first wall segment <NUM> that extends at the first angle α1 relative to the build direction BD, which is different and greater than the second angle α2 of the second wall segment <NUM>. The second wall segment <NUM> also extends at the second angle β2 relative to the first wall segment <NUM>, which is different and less than the third angle β3 defined between the second wall segment <NUM> and the third wall segment <NUM>. The third wall segment <NUM> extends at the third angle α3 relative to the build direction BD, which is different and greater than the second angle α2 of the second wall segment <NUM> and the fourth angle α4 of the fourth wall segment <NUM>. The third wall segment <NUM> also extends at the fourth angle β4 relative to the fourth wall segment <NUM>, which is different and less than the fifth angle β5 defined between the fourth wall segment <NUM> and the fifth wall segment <NUM>. The fourth wall segment <NUM> extends at the fourth angle α4 relative to the build direction BD, which is different and less than the fifth angle α5 of the fifth wall segment <NUM>.

As discussed, each of the wall segments <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, 528a, 528b and 528c associated with the outer liner wall <NUM> have the double wall, with the inner wall <NUM> opposite the outer wall <NUM> that defines the intervening cavity <NUM> between the inner wall <NUM> and the outer wall <NUM>. In this example, the double wall including the effusion cooling system <NUM> is the same between the outer liner <NUM> and the inner liner <NUM> of the combustor <NUM>, and is the same between the outer liner <NUM> and the inner liner <NUM> of the combustor <NUM>. Thus, the double wall and the effusion cooling system <NUM> associated with the outer liner <NUM> and the inner liner <NUM> will not be discussed in detail herein. Briefly, with reference to <FIG>, the inner wall surface 230a of the outer liner <NUM> is shown. The inner wall <NUM> is opposite the outer wall <NUM> defines the intervening cavity <NUM> between the inner wall <NUM> and the outer wall <NUM>. The effusion cooling system <NUM> is defined between the inner wall <NUM> and the outer wall <NUM> of each of wall segments <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, 528a, 528b. With reference back to <FIG>, the effusion cooling system <NUM> includes the plurality of pedestals <NUM>, the plurality of impingement cooling holes <NUM> and the plurality of effusion cooling passages <NUM>.

With reference to <FIG>, the inner liner wall <NUM> is shown in greater detail. In one example, the inner liner wall <NUM> is composed of a plurality of inner liner wall segments <NUM>, including: the first inner wall segment <NUM>, the second inner wall segment <NUM>, the third inner wall segment <NUM>, the fourth inner wall segment <NUM>, the fifth inner wall segment <NUM> and a sixth inner wall segment <NUM>. Each of the first inner wall segment <NUM>, the second inner wall segment <NUM>, the third inner wall segment <NUM>, the fourth inner wall segment <NUM>, the fifth inner wall segment <NUM> and the sixth inner wall segment <NUM> have the double wall, with the inner wall <NUM> opposite the outer wall <NUM>. It should be noted that the inner wall surface 230a of the inner liner <NUM> is the same as the inner wall surface 230a of the inner liner <NUM> shown in <FIG>, and as discussed, the double wall and the effusion cooling system <NUM> associated with the inner liner <NUM> will not be discussed in detail herein. Briefly, the inner wall <NUM> opposite the outer wall <NUM> defines the intervening cavity <NUM> between the inner wall <NUM> and the outer wall <NUM>. The effusion cooling system <NUM> is defined between the inner wall <NUM> and the outer wall <NUM> of each of the first inner wall segment <NUM>, the second inner wall segment <NUM>, the third inner wall segment <NUM>, the fourth inner wall segment <NUM>, the fifth inner wall segment <NUM> and a sixth inner wall segment <NUM>.

The first inner wall segment <NUM> is defined at the first inner end <NUM>, and extends for the ninth distance D9. The ninth distance D9 is predetermined such that the first inner wall segment <NUM> is spaced a distance apart from the first sub-segment 228a of the sixth wall segment <NUM> of the outer liner <NUM> to form the passageway <NUM>. The first inner wall segment <NUM> extends along the ninth distance D9 so as to be opposite a portion of the second wall segment <NUM> and the third wall segment <NUM>. The first inner wall segment <NUM> has the ninth angle α9 relative to the build direction BD. The first inner wall segment <NUM> is connected to or integrally formed with the second inner wall segment <NUM> and the sixth inner wall segment <NUM>. The first inner wall segment <NUM> includes the one or more quench holes <NUM>.

The second inner wall segment <NUM> extends for the tenth distance D10. The second wall segment <NUM> extends at the tenth angle α10 relative to the build direction BD. The second inner wall segment <NUM> also extends at the tenth angle β10 relative to the first inner wall segment <NUM>. The third inner wall segment <NUM> extends for the eleventh distance D11. The eleventh distance D11 cooperates with the tenth distance D10 such that the second inner wall segment <NUM> and the third inner wall segment <NUM> are substantially opposite the fuel injector holes <NUM>. The third inner wall segment <NUM> extends at the eleventh angle α11 relative to the build direction BD. The third inner wall segment <NUM> also extends at the eleventh angle β11 relative to the second inner wall segment <NUM>.

The fourth inner wall segment <NUM> extends for the twelfth distance D12. The fourth inner wall segment <NUM> is substantially opposite the fourth wall segment <NUM> of the outer liner <NUM>. The fourth inner wall segment <NUM> extends at the twelfth angle α12 relative to the build direction BD. The fourth wall segment <NUM> also extends at the twelfth angle β12 relative to the third inner wall segment <NUM>. The fifth inner wall segment <NUM> extends for the thirteenth distance D13. The fifth inner wall segment <NUM> extends at the thirteenth angle α13 relative to the build direction BD. In this example, the thirteenth angle α13 is about <NUM> degrees. The fifth inner wall segment <NUM> also extends at the thirteenth angle β13 relative to the fourth inner wall segment <NUM>. The fifth inner wall segment <NUM> extends for about the same length as the fifth wall segment <NUM> of the outer liner <NUM> to facilitate coupling or joining the inner liner <NUM> to the outer liner <NUM> at the respective second ends <NUM>, <NUM>.

The sixth inner wall segment <NUM> is connected to or integrally formed with the first inner wall segment <NUM> and extends axially inward at the first inner end <NUM> of the inner liner <NUM>. The sixth inner wall segment <NUM> extends for a fourteenth distance DT14, which is different and less than the distances D8-D12. The sixth inner wall segment <NUM> extends at a fourteenth angle αT14 relative to the build direction BD. In this example, the fourteenth angle αT14 is about <NUM> degrees. In one example the sixth inner wall segment <NUM> is integrally formed with the first inner wall segment <NUM> such that the sixth inner wall segment <NUM> is substantially parallel to the first inner wall segment <NUM>. The sixth inner wall segment <NUM> includes two radially inward extending flanges 622a, 622b, which assist in coupling the combustor <NUM> within the gas turbine engine <NUM>.

Thus, in this example, the inner liner <NUM> has the first inner wall segment <NUM> that extends along the ninth axis A9, which is substantially parallel to the longitudinal axis <NUM>. The second inner wall segment <NUM> extends along the tenth axis A10, which is transverse or oblique to the ninth axis A9 and the longitudinal axis <NUM>. The third inner wall segment <NUM> extends along the eleventh axis A11, which is substantially parallel to the longitudinal axis <NUM> and transverse to the tenth axis A10. The fourth inner wall segment <NUM> extends along the twelfth axis A12, which is transverse or oblique to the eleventh axis A11 and the longitudinal axis <NUM>. The fifth inner wall segment <NUM> extends along the thirteenth axis A13, which is substantially parallel to the longitudinal axis <NUM> and transverse to the eleventh axis A11. The sixth inner wall segment <NUM> extends along a fourteenth axis AT14, which is substantially parallel to the ninth axis A9 and the longitudinal axis <NUM>. The axes A10 and A12 are each transverse to the build direction BD, and the axes A9, AT14 and A13 are each substantially parallel to the build direction BD.

With reference to <FIG>, a flowchart illustrates an exemplary method <NUM> for manufacturing the combustor <NUM>, <NUM>. In one example, the method begins at <NUM>. At <NUM>, the method proceeds with forming the outer liner <NUM>, <NUM>, and at <NUM>, the method proceeds with forming the inner liner <NUM>, <NUM> nested within the outer liner <NUM>, <NUM>. While identified as different blocks <NUM>, <NUM>, the method forms the inner liner <NUM>, <NUM> substantially concurrently with the forming of the outer liner <NUM>, <NUM> in a single build. Generally, the inner liner <NUM>, <NUM> is formed substantially concurrently with the forming of the respective outer liner <NUM>, <NUM> so as to be nested within the outer liner wall <NUM>, <NUM> of the outer liner <NUM>, <NUM>. The inner liner <NUM>, <NUM> and the respective outer liner <NUM>, <NUM> are composed of a metal or metal alloy, including, but not limited to Haynes® <NUM> alloy, Inconel <NUM> and Hastelloy®-X. In this example, the inner liner <NUM>, <NUM> and the respective outer liner <NUM>, <NUM> are formed in a single build using additive manufacturing, including, but not limited to direct metal laser sintering (DMLS), laser powder bed fusion (L-PBF), electron powder bed fusion (E-PBF) or electron beam melting (EBM). The inner liner <NUM>, <NUM> and the outer liner <NUM>, <NUM> are each formed through additive manufacturing to include the outer liner wall <NUM>, <NUM> and the inner liner wall <NUM>, <NUM>, respectively, with the double wall that includes the effusion cooling system <NUM>.

With the inner liner <NUM>, <NUM> formed so as to be nested within the outer liner wall <NUM>, <NUM> of the respective outer liner <NUM>, <NUM>, at <NUM>, the inner liner <NUM>, <NUM> may be removed from the outer liner <NUM>, <NUM> and one or both of the inner liner <NUM>, <NUM> and the outer liner <NUM>, <NUM> may be subjected to additional processing. For example, one or both of the inner liner <NUM>, <NUM> and the respective outer liner <NUM>, <NUM> may be subjected to stress relief, heat treatment, hot isostatic pressing (HIP), the application of one or more coatings, such as a thermal barrier coating as described in commonly assigned <CIT>, previously incorporated herein by reference, and the like. Once the additional processing is completed, at <NUM>, the inner liner <NUM>, <NUM> is coupled to the respective outer liner <NUM>, <NUM> at the second ends <NUM>, <NUM> to enclose the combustion chamber <NUM>, <NUM>. In one example, the second ends <NUM>, <NUM> are coupled together via welding. At <NUM>, an additional wall segment, such as the sixth wall segment <NUM>, <NUM> is coupled to the first wall segment <NUM> of the respective outer liner <NUM>, <NUM> via welding, for example. Generally, the sixth wall segment <NUM>, <NUM> is composed of a metal or metal alloy, including, but not limited to Haynes® <NUM> alloy, Inconel <NUM> and Hastelloy®-X. The sixth wall segment <NUM>, <NUM> is formed using additive manufacturing including, but not limited to direct metal laser sintering (DMLS), laser powder bed fusion (L-PBF), electron powder bed fusion (E-PBF) or electron beam melting (EBM). The sixth wall segment <NUM>, <NUM> is described herein as being separately formed and coupled to the first wall segment <NUM>, however, in other examples, the sixth wall segment <NUM>, <NUM> may be integrally formed with the first wall segment <NUM> if desired. At <NUM>, the manufacture of the combustor <NUM>, <NUM> is complete, and the combustor <NUM>, <NUM> may be installed in the respective gas turbine engine <NUM>, <NUM>.

Once installed in the respective gas turbine engine <NUM>, <NUM>, generally, during operation of the respective gas turbine engine <NUM>, <NUM>, pressurized air from the compressor section <NUM>, <NUM> is intermixed with fuel introduced through the fuel injectors and ignited by an igniter (not shown) to support initial combustion within the respective combustor <NUM>, <NUM>. Additional air for further combustion flows from the plenum <NUM>, <NUM> into the combustion chamber <NUM>, <NUM> through the quench holes <NUM>. Air from the plenum <NUM>, <NUM> also enters the impingement cooling holes <NUM>, and flows through the effusion cooling passages <NUM> to generate a film of cooling fluid along the hot walls or inner wall surfaces 230a of the inner liner <NUM>, <NUM> and the respective outer liner <NUM>, <NUM>.

Thus, the structure of the combustor <NUM>, <NUM> enables the combustor <NUM>, <NUM> to be additively manufactured with the inner liner <NUM>, <NUM> formed substantially concurrently with the forming of the outer liner <NUM>, <NUM>. By forming the inner liner <NUM>, <NUM> nested within the outer liner <NUM>, <NUM> substantially concurrently, a single additive manufacturing process may be performed to produce a substantial majority of the combustor <NUM>, <NUM>, which reduces cost and manufacturing time. In addition, by additively manufacturing the combustor <NUM>, <NUM>, the effusion cooling system <NUM> (<FIG>) may be defined in the double wall of both of the inner liner <NUM>, <NUM> and the respective outer liner <NUM>, <NUM>, which improves cooling of the combustor <NUM>, <NUM> and thereby increases a life of the combustor <NUM>, <NUM> while reducing maintenance costs. The improved cooling of the combustor <NUM>, <NUM> also enables the combustor <NUM>, <NUM> to be used in higher temperature or high performance applications. In addition, the shape of the combustor <NUM>, <NUM> enables the combustor <NUM>, <NUM> to be additively manufactured without requiring supports or to be self-supporting during additive manufacturing. The shape or structure of the combustor <NUM>, <NUM> also provides reduced parts and reduced leakage, as by additively manufacturing the inner liner <NUM>, <NUM> and the outer liner <NUM>, <NUM> to be one-piece or monolithic, additional parts and seals are not needed. In addition, the one-piece or monolithic inner liner <NUM>, <NUM> and outer liner <NUM>, <NUM> reduces a weight associated with the combustor <NUM>, <NUM>. The sixth wall segments <NUM>, <NUM> also provide an improved interface for the turbine nozzle associated with the turbine section <NUM>, <NUM>.

Claim 1:
A combustor for a gas turbine engine, comprising:
an outer liner (<NUM>, <NUM>) having a first end and a second end opposite the first end, the first end interconnected to the second end by an outer liner wall (<NUM>, <NUM>) composed of a plurality of outer wall segments, wherein the outer wall segments are straight; and
an inner liner (<NUM>, <NUM>) having a first inner end and a second inner end opposite the first inner end, the second inner end coupled to the second end of the outer liner, the first inner end interconnected to the second inner end by an inner liner wall (<NUM>, <NUM>) composed of a plurality of inner wall segments, wherein the inner wall segments are straight,
wherein each of the outer liner wall (<NUM>, <NUM>) and the inner liner wall (<NUM>, <NUM>) cooperate to define a combustion chamber (<NUM>, <NUM>), and wherein the plurality of outer wall segments comprises a first wall segment (<NUM>) at the first end of the outer liner (<NUM>, <NUM>), the first wall segment (<NUM>) extending at an angle of about <NUM> degrees relative to a build direction of the combustor, wherein the build direction extends in an axial direction A and is perpendicular to a radial direction R,
a second wall segment (<NUM>) connected to or integrally formed with the first wall segment (<NUM>), the second wall segment extending at an angle of about <NUM> degrees relative to the build direction of the combustor, a third wall segment (<NUM>) connected to or integrally formed with the second wall segment (<NUM>), the third wall segment extending substantially parallel to the build direction of the combustor, a fourth wall segment (<NUM>) connected to or integrally formed with the third wall segment (<NUM>), the fourth wall segment extending at an angle of about <NUM> degrees relative to the build direction of the combustor, and a fifth wall segment (<NUM>) connected to or integrally formed with the further wall segment (<NUM>), the fifth wall segment extending substantially parallel to the build direction of the combustor and terminating at the second end (<NUM>) of the outer liner.