EP4728171A1

EP4728171A1 - Cooled double wall component of a gas turbine engine

Info

Publication number: EP4728171A1
Application number: EP24748083.3A
Authority: EP
Inventors: Johannes Albert; Jan Münzer
Original assignee: Siemens Energy Global GmbH and Co KG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2023-08-04
Filing date: 2024-07-25
Publication date: 2026-04-22
Also published as: WO2025031821A1; GB2632332A; GB202311978D0; CN121666482A; KR20260040330A

Abstract

A component includes a first wall, a second wall having a second wall thickness and positioned at a distance from the first wall, a coating applied to the first wall, a hole formed in the coating and the first wall, the hole defining a hole centerline, and a bulge coupled to the second wall and intersecting the hole centerline, the bulge cooperating with the second wall to define a bulge thickness that is greater than the second wall thickness.

Description

COOLED DOUBLE WALL COMPONENT OF A GAS TURBINE ENGINE

BACKGROUND

[0001] A gas turbine engine typically includes a compressor section, a turbine section, and a combustion section disposed therebetween. The compressor section includes multiple stages of rotating compressor blades and stationary compressor vanes. The combustion section typically includes a plurality of combustors. The turbine section includes multiple stages of rotating turbine blades and stationary turbine vanes. Turbine blades and vanes often operate in a high temperature environment and are internally cooled.

[0002] A component of the gas turbine engine, such as the combustor, the rotating turbine blades, and the stationary turbine vanes, etc., may have a double wall that defines a plenum therebetween. During operation of the gas turbine engine, the component experiences a high temperature. A hole may be formed in one wall of the double wall to pass through a cooling fluid into the plenum to cool the component. A coating may be applied to the wall which may cover the hole. The hole needs to be reopened. A thickness of the other wall of the double wall may be reduced during the reopening process.

BRIEF SUMMARY

[0003] In one aspect, a component is provided. The component includes a first wall, a second wall having a second wall thickness and positioned at a distance from the first wall, a coating applied to the first wall, a hole formed in the coating and the first wall, the hole defining a hole centerline, and a bulge coupled to the second wall and intersecting the hole centerline, the bulge cooperating with the second wall to define a bulge thickness that is greater than the second wall thickness. [0004] In one aspect, a method for manufacturing a component is provided. The method includes positioning a first wall, positioning a second wall at a distance from the first wall, the second wall having a second wall thickness, forming a hole in the first wall, the hole defining a hole centerline, applying a coating to the first wall, a portion of the coating covering the hole, coupling a bulge to the second wall such that the bulge intersects the hole centerline, and removing the portion of the coating that covers the hole.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0006] FIG. 1 illustrates a longitudinal cross-sectional view of a gas turbine engine taken along a plane that contains a longitudinal axis or central axis.

[0007] FIG. 2 illustrates a schematic section view of a component suitable for use with the gas turbine engine of FIG. 1.

[0008] FIG. 3 illustrates a schematic section view of the component of FIG. 2 having a coating.

[0009] FIG. 4 illustrates a schematic section view of the component of FIG. 3 at a start condition of a process of reopening the hole.

[0010] FIG. 5 illustrates a schematic section view of the component of FIG. 3 at an end condition of the process of reopening the hole.

[0011] FIG. 6 illustrates a schematic section view of the component of FIG. 3 at an operation condition.

[0012] FIG. 7 illustrates another schematic section view of the component.

[0013] FIG. 8 illustrates a schematic section view of the component of FIG. 7 having a coating. [0014] FIG. 9 illustrates a schematic section view of the component of FIG. 7 at an operation condition.

DETAILED DESCRIPTION

[0015] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in this description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0016] Various technologies that pertain to systems and methods will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed by multiple elements. Similarly, for instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0017] Also, it should be understood that the words or phrases used herein should be construed broadly, unless expressly limited in some examples. For example, the terms “including”, “having”, and “comprising”, as well as derivatives thereof, mean inclusion without limitation. The singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The term “or” is inclusive, meaning and/or, unless the context clearly indicates otherwise. The phrases “associated with” and “associated therewith” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like.

Furthermore, while multiple embodiments or constructions may be described herein, any features, methods, steps, components, etc. described with regard to one embodiment are equally applicable to other embodiments absent a specific statement to the contrary.

[0018] Also, although the terms “first”, “second”, “third” and so forth may be used herein to refer to various elements, information, functions, or acts, these elements, information, functions, or acts should not be limited by these terms. Rather these numeral adjectives are used to distinguish different elements, information, functions or acts from each other. For example, a first element, information, function, or act could be termed a second element, information, function, or act, and, similarly, a second element, information, function, or act could be termed a first element, information, function, or act, without departing from the scope of the present disclosure.

[0019] Also, in the description, the terms “axial” or “axially” refer to a direction along a longitudinal axis of a gas turbine engine. The terms “radial” or “radially” refer to a direction perpendicular to the longitudinal axis of the gas turbine engine. The terms “downstream” or “aft” refer to a direction along a flow direction. The terms “upstream” or “forward” refer to a direction against the flow direction.

[0020] In addition, the term “adjacent to" may mean that an element is relatively near to but not in contact with a further element or that the element is in contact with the further portion, unless the context clearly indicates otherwise. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Terms “about” or “substantially” or like terms are intended to cover variations in a value that are within normal industry manufacturing tolerances for that dimension. If no industry standard is available, a variation of twenty percent would fall within the meaning of these terms unless otherwise stated.

[0021] FIG. 1 illustrates an example of a gas turbine engine 100 including a compressor section 102, a combustion section 104, and a turbine section 106 arranged along a central axis 112. The compressor section 102 includes a plurality of compressor stages 114 with each compressor stage 114 including a set of stationary compressor vanes 116 or adjustable guide vanes and a set of rotating compressor blades 118. A rotor 134 supports the rotating compressor blades 118 for rotation about the central axis 112 during operation. In some constructions, a single one-piece rotor 134 extends the length of the gas turbine engine 100 and is supported for rotation by a bearing at either end. In other constructions, the rotor 134 is assembled from several separate spools that are attached to one another or may include multiple disk sections that are attached via a bolt or plurality of bolts.

[0022] The compressor section 102 is in fluid communication with an inlet section 108 to allow the gas turbine engine 100 to draw atmospheric air into the compressor section 102. During operation of the gas turbine engine 100, the compressor section 102 draws in atmospheric air and compresses that air for delivery to the combustion section 104. The illustrated compressor section 102 is an example of one compressor section 102 with other arrangements and designs being possible.

[0023] In the illustrated construction, the combustion section 104 includes a plurality of separate combustors 120 that each operate to mix a flow of fuel with the compressed air from the compressor section 102 and to combust that air-fuel mixture to produce a flow of high temperature, high pressure combustion gases or exhaust gas 122. Of course, many other arrangements of the combustion section 104 are possible.

[0024] The turbine section 106 includes a plurality of turbine stages 124 with each turbine stage 124 including a number of stationary turbine vanes 126 and a number of rotating turbine blades 128. The turbine stages 124 are arranged to receive the exhaust gas 122 from the combustion section 104 at a turbine inlet 130 and expand that gas to convert thermal and pressure energy into rotating or mechanical work. The turbine section 106 is connected to the compressor section 102 to drive the compressor section 102. For gas turbine engines 100 used for power generation or as prime movers, the turbine section 106 is also connected to a generator, pump, or other device to be driven. As with the compressor section 102, other designs and arrangements of the turbine section 106 are possible.

[0025] An exhaust portion 110 is positioned downstream of the turbine section 106 and is arranged to receive the expanded flow of exhaust gas 122 from the final turbine stage 124 in the turbine section 106. The exhaust portion 110 is arranged to efficiently direct the exhaust gas 122 away from the turbine section 106 to assure efficient operation of the turbine section 106. Many variations and design differences are possible in the exhaust portion 110. As such, the illustrated exhaust portion 110 is but one example of those variations.

[0026] A control system 132 is coupled to the gas turbine engine 100 and operates to monitor various operating parameters and to control various operations of the gas turbine engine 100. In preferred constructions the control system 132 is typically micro-processor based and includes memory devices and data storage devices for collecting, analyzing, and storing data. In addition, the control system 132 provides output data to various devices including monitors, printers, indicators, and the like that allow users to interface with the control system 132 to provide inputs or adjustments. In the example of a power generation system, a user may input a power output set point and the control system 132 may adjust the various control inputs to achieve that power output in an efficient manner.

[0027] The control system 132 can control various operating parameters including, but not limited to variable inlet guide vane positions, fuel flow rates and pressures, engine speed, valve positions, generator load, and generator excitation. Of course, other applications may have fewer or more controllable devices. The control system 132 also monitors various parameters to assure that the gas turbine engine 100 is operating properly. Some parameters that are monitored may include inlet air temperature, compressor outlet temperature and pressure, combustor outlet temperature, fuel flow rate, generator power output, bearing temperature, and the like. Many of these measurements are displayed for the user and are logged for later review should such a review be necessary.

[0028] FIG. 2 illustrates a schematic section view of a component 200. The component 200 may be a component of the gas turbine engine 100, such as the combustor 120, the stationary turbine vane 126, the rotating turbine blade 128, or any other suitable components.

[0029] The component 200 has a double wall including a first wall 202 and a second wall 204 that is positioned at a distance from the first wall 202. A plenum 206 is defined between the first wall 202 and the second wall 204. The plenum 206 can also be formed by an inner channel inside a single wall. In this arrangement, the plenum 206 divides the single wall into the first wall 202 and the second wall 204. [0030] The first wall 202 has a first wall inner surface 214 facing toward the plenum 206 and a first wall outer surface 216 opposite to the first wall inner surface 214 and facing away from the plenum 206. A hole 208 is formed in the first wall 202 that perforates through the first wall 202 from the first wall outer surface 216 to the first wall inner surface 214. The hole 208 defines a hole centerline 212.

[0031] The second wall 204 has a second wall inner surface 218 facing to the first wall inner surface 214 and toward the plenum 206 and a second wall outer surface 220 opposite to the second wall inner surface 218 and facing away from the plenum 206. The second wall 204 has a second wall thickness that is defined as the shortest distance between the second wall inner surface 218 and the second wall outer surface 220.

[0032] A bulge 210 is coupled to the second wall 204 at the second wall outer surface 220 and intersects with the hole centerline 212. The bulge 210 has a bulge outer surface 224 facing away from the plenum 206. The bulge 210 cooperates with the second wall 204 to define a bulge thickness that is a linear distance between the second wall inner surface 218 and the bulge outer surface 224. The bulge thickness is greater than the second wall thickness. The bulge thickness varies along the second wall 204. In other constructions, the bulge thickness may be the same along the second wall 204.

[0033] The bulge 210 has a semi-circular cross section. The bulge 210 defines a bulge centerline 222 that is colinear with the hole centerline 212. In other constructions, the bulge 210 may have other cross section shape other than semi-circular, such as oval, rectangular, etc. The bulge 210 and the second wall 204 include the same material. The bulge 210 and the second wall 204 include the same material and are formed in a single continuous process. The bulge 210 and the second wall 204 are formed by an additive manufacturing, such as or similar to a selective laser melting in layer-by-layer process. In other constructions, the bulge 210 and the second wall 204 may be formed by other single continuous process, such as casting, machining, forming, etc. The bulge 210 and the second wall 204 may also include different materials and/or may be formed as two separated pieces and jointed together, such as by welding or other jointing methods.

[0034] The first wall 202, the second wall 204, and the bulge 210 include the same material.

The first wall 202, the second wall 204, the hole 208, and the bulge 210 are formed in a single continuous process. The first wall 202, the second wall 204, the hole 208, and the bulge 210 are formed by an additive manufacturing, such as or similar to a selective laser melting in layer-by-layer process. In other constructions, the first wall 202, the second wall 204, the hole 208, and the bulge 210 may be formed by other single continuous process, such as casting, machining, forming, etc. The first wall 202, the second wall 204, and the bulge 210 may also include different materials and/or may be formed as separated pieces and jointed together, such as by welding or other jointing methods.

[0035] FIG. 3. Illustrates a schematic section view of the component 200 having a coating 302. The coating 302 is applied to the first wall 202 at the first wall outer surface 216. A portion of the coating 302 covers the hole 208.

[0036] The coating 302 has a coating inner surface 304 that is coupled to the first wall outer surface 216. The coating 302 has a coating outer surface 306 that is opposite to the coating inner surface 304. The coating 302 defines a coating thickness that is the shortest distance between the coating inner surface 304 and the coating outer surface 306. The coating thickness may vary along the first wall 202. The coating 302 is a thermal barrier coating, with other coatings possible. In other constructions, the coating 302 may cover a portion of the hole 208.

[0037] FIG. 4 illustrates a schematic section view of the component 200 of FIG. 3 at a start condition of a process of reopening the hole 208. A drill 402 is used to remove the portion of the coating 302 that covers the hole 208. The drill 402 is a laser drill that produces a laser beam 404. The laser beam 404 may be a continuous laser beam or pulses of laser beams. In other constructions, the drill 402 may be other types of drills, for example, the drill 402 may have a physical rotating cutting tool, such as a drill bit.

[0038] FIG. 5 illustrates a schematic section view of the component 200 of FIG. 3 at an end condition of the process of reopening the hole 208. The portion of the coating 302 that coverts the hole 208 is removed by the laser beam 404. The hole 208 is reopened and extends through the coating 302 and the first wall 202. The laser beam 404 may pass through the hole 208 and the plenum 206 and hit the second wall 204.

[0039] FIG. 6 illustrates a schematic section view of the component 200 of FIG. 3 at an operation condition. The hole 208 extends through the coating 302 and the first wall 202. A blind hole 602 is formed in the second wall 204 having a blind hole end surface 604. The blind hole 602 is formed by the laser beam 404 during the step of removing the portion of the coating 302 that covers the hole 208.

[0040] The blind hole 602 defines a blind hole centerline 606 that is colinear with the hole centerline 212. The blind hole 602 and the bulge 210 cooperate to define a minimum wall thickness that is the shortest distance between the blind hole end surface 604 and the bulge outer surface 224. The minimum wall thickness is equal to or greater than the second wall thickness.

[0041] FIG. 7 illustrates another schematic section view of the component 200. The component 200 includes a plurality of holes 208 that are formed in the first wall 202 and perforate through the first wall 202 from the first wall outer surface 216 to the first wall inner surface 214. The plurality of holes 208 are distributed along the first wall 202 and spaced apart from each other. Each hole 208 of the plurality of holes 208 defines a hole centerline 212.

[0042] A plurality of bulges 210 are coupled to the second wall 204 at the second wall outer surface 220. Each bulge 210 of the plurality of bulges 210 has a semi-circular cross section. Each bulge 210 defines a bulge centerline 222 that is colinear with a corresponding hole centerline 212. Each bulge 210 has a bulge outer surface 224 facing away from the plenum 206. Each bulge 210 cooperates with the second wall 204 to define a bulge thickness that is a linear distance between the second wall inner surface 218 and the bulge outer surface 224. The bulge thickness is greater than the second wall thickness.

[0043] The plurality of bulges 210 have the same cross section shape, the same dimension, and the same material. In other constructions, the plurality of bulges 210 may have the same cross section shape other than semi-circular, such as oval, rectangular, etc. The plurality of bulges 210 may have different cross section shapes, different dimensions, and/or different materials from each other.

[0044] The plurality of bulges 210 and the second wall 204 include the same material and are formed in a single continuous process. The plurality of bulges 210 and the second wall 204 are formed by an additive manufacturing, such as or similar to a selective laser melting in layer-by- layer process. In other constructions, the plurality of bulges 210 and the second wall 204 may be formed by other single continuous process, such as casting, machining, forming, etc. The plurality of bulges 210 and the second wall 204 may also include different materials and/or may be formed as two separated pieces and jointed together, such as by welding or other jointing methods.

[0045] The first wall 202, the second wall 204, and the plurality of bulges 210 include the same material. The first wall 202, the second wall 204, the plurality of holes 208, and the plurality of bulges 210 are formed in a single continuous process. The first wall 202, the second wall 204, the plurality of holes 208, and the plurality of bulges 210 are formed by an additive manufacturing, such as or similar to a selective laser melting in layer-by-layer process. In other constructions, the first wall 202, the second wall 204, the plurality of holes 208, and the plurality of bulges 210 are formed in a single continuous process other than the additive manufacturing, such as casting, machining, forming, etc. The first wall 202, the second wall 204, and the plurality of bulges 210 may also include different materials and/or may be formed as separated pieces and jointed together, such as by welding or other jointing methods.

[0046] FIG. 8 illustrates a schematic section view of the component 200 of FIG. 7 having a coating 302. The coating 302 is applied to the first wall 202 at the first wall outer surface 216. The coating inner surface 304 is coupled to the first wall outer surface 216. A portion of the coating 302 covers a corresponding hole 208.

[0047] The coating thickness is the shortest distance between the coating inner surface 304 and the coating outer surface 306. The coating thickness varies along the first wall 202. In the construction of FIG. 8, the coating thickness reduces from one end of the first wall 202 to the other end of the first wall 202. In other constructions, the coating thickness may fluctuate along the first wall 202. The coating 302 may be a thermal barrier coating, with other coatings possible.

[0048] FIG. 9 illustrates a schematic section view of the component 200 of FIG. 7 at an operation condition. The plurality of holes 208 are reopened by the process as descripted in FIG. 4 and FIG. 5. The plurality of holes 208 are reopened and extend through the coating 302 and the first wall 202. [0049] A plurality of blind holes 602 are formed in the second wall 204 and/or in the second wall 204 and the bulge 210 during the step of removing the portions of the coating 302 that cover the plurality of holes 208. Each blind hole 602 of the plurality of blind holes 602 has a blind hole end surface 604. Each blind hole 602 defines a blind hole centerline 606 that is colinear with the hole centerline 212. Each blind hole 602 and a corresponding bulge 210 cooperate to define a minimum wall thickness that is the shortest distance between the blind hole end surface 604 and the bulge outer surface 224. The minimum wall thickness is equal to or greater than the second wall thickness. The minimum wall thickness varies for each blind hole 602 and a corresponding bulge 210. In other constructions, the minimum wall thickness may be the same for the plurality of blind holes 602 and corresponding bulges 210.

[0050] During manufacturing, the component 200 is first formed with the hole 208 perforating through the first wall 202. The coating 302 is then applied to the first wall 202 and a portion of the coating 302 covers the hole 208. The portion of the coating 302 that covers the hole 208 is then removed to reopen the hole 208. A power of the drill 402 is set to remove the portion of the coating 302 that covers the hole 208. The laser beam 404 of the drill 402 may pass through the hole 208 and hit the second wall 204 at an area intersecting the hole centerline 212 during the step of removing the portion of the coating 302. This may happen due to a variation of the coating thickness. As such, the second wall thickness may be reduced at the area intersecting the hole centerline 212 when reopening the hole 208. The bulge 210 is coupled to the second wall 204 at the area intersecting the hole centerline 212. The bulge 210 is a local material accumulation on the second wall 204 to ensure a minimum wall thickness is maintained to adapt to the variation of the coating thickness. The minimum wall thickness is equal to or greater than the second wall thickness. The bulge 210 reduces a complication of production of a coated double wall component 200 with a hole 208 while maintaining the minimum wall thickness. No bulge 210 is coupled to the second wall 204 at an area that does not intersect the hole centerline 212 which reduces a cost of material. The component 200 including the first wall 202, the second wall 204, the hole 208, and the bulge 210 may be manufactured by a single continuous process, such as the additive manufacturing.

[0051] The component 200 may be a component of the gas turbine engine 100, such as the combustor 120, the stationary turbine vane 126, the rotating turbine blade 128, or any double wall component with hole. The plenum 206 may be an internal cooling channel. The hole 208 may be a cooling hole to pass through a cooling fluid into or out of the plenum 206 to cool the turbine component. The hole 208 may be an impingement cooling hole or a film cooling hole of the turbine component.

[0052] Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0053] None of the description in the present application should be read as implying that any particular element, step, act, or function is an essential element, which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke a means plus function claim construction unless the exact words "means for" are followed by a participle.

LISTING OF DRAWING ELEMENTS

100 gas turbine engine

102 compressor section

104 combustion section

106 turbine section

108 inlet section

110 exhaust portion

112 central axis

114 compressor stage

116 stationary compressor vane

118 rotating compressor blade combustor exhaust gas turbine stage stationary turbine vane rotating turbine blade turbine inlet control system rotor component first wall second wall plenum hole bulge hole centerline first wall inner surface first wall outer surface second wall inner surface second wall outer surface bulge centerline bulge outer surface coating coating inner surface coating outer surface drill laser beam blind hole blind hole end surface blind hole centerline

Claims

CLAIMS What is claimed is:

1. A component comprises: a first wall; a second wall having a second wall thickness and positioned at a distance from the first wall; a coating applied to the first wall; a hole formed in the coating and the first wall, the hole defining a hole centerline; and a bulge coupled to the second wall and intersecting the hole centerline, the bulge cooperating with the second wall to define a bulge thickness that is greater than the second wall thickness.

2. The component of claim 1, wherein the bulge comprises a semi-circular cross section.

3. The component of claim 1, wherein the bulge defines a bulge centerline that is colinear with the hole centerline.

4. The component of claim 1, further comprising a blind hole that is formed in the second wall, wherein the blind hole defines a blind hole centerline that is colinear with the hole centerline.

5. The component of claim 4, wherein the blind hole and the bulge cooperate to define a minimum wall thickness that is equal to or greater than the second wall thickness.

6. The component of claim 5, wherein the blind hole comprises a blind hole end surface, wherein the bulge comprises a bulge outer surface, and wherein the minimum wall thickness is the shortest distance between the blind hole end surface and the bulge outer surface.

7. The component of claim 1, wherein the first wall, the second wall, the hole, and the bulge are formed in a single continuous process.

8. The component of claim 1, wherein the coating defines a coating thickness that varies along the first wall.

9. The component of claim 1, wherein the component is a component of a gas turbine engine, and wherein the hole is a cooling hole.

10. A method for manufacturing a component, the method comprising: positioning a first wall; positioning a second wall at a distance from the first wall, the second wall having a second wall thickness; forming a hole in the first wall, the hole defining a hole centerline; applying a coating to the first wall, a portion of the coating covering the hole; coupling a bulge to the second wall such that the bulge intersects the hole centerline; and removing the portion of the coating that covers the hole.

11. The method of claim 10, further comprising forming the bulge having a semicircular cross section.

12. The method of claim 10, wherein the bulge defines a bulge centerline, and wherein the coupling step further comprises aligning the bulge centerline with the hole centerline so that they are colinear.

13. The method of claim 10, further comprising forming a blind hole in the second wall, wherein the blind hole defines a blind hole centerline that is colinear with the hole centerline.

14. The method of claim 13, wherein the blind hole is formed during the removing step.

15. The method of claim 13, wherein the blind hole and the bulge cooperate to define a minimum wall thickness that is equal to or greater than the second wall thickness.

16. The method of claim 15, wherein the blind hole comprises a blind hole end surface, wherein the bulge comprises a bulge outer surface, and wherein the minimum wall thickness is the shortest distance between the blind hole end surface and the bulge outer surface.

17. The method of claim 10, wherein the removing step is performed using a laser drilling process.

18. The method of claim 10, wherein the coupling step further comprises forming the second wall and the bulge in a single continuous process.

19. The method of claim 10, further comprising forming the first wall, the second wall, the hole, and the bulge in a single continuous process.

20. The method of claim 10, further comprising forming the first wall, the second wall, the hole, and the bulge using an additive manufacturing.