Component with cooling channels for turbine engine

Abstract

An apparatus and method for an engine component of a turbine engine having a working gas stream separated into a cooling gas stream and a combustion gas stream. The engine component includes a wall defining an interior and having an outer surface. The tip wall spans the first side and the second side of the wall to enclose the interior. A tip track extends from the tip wall and has an inner tip track surface that, in combination with the tip wall, at least partially defines a region defining the plenum. A rim is formed in at least one of the outer surface and the inner tip track surface.

Description

[0001] This application is a continuation-in-part of the application for Patent titled “Component with Cooling Passages for a Turbine Engine” filed on September 26, 2022, having application number 202211175798.4.

[0002] Cross Reference to Related Applications

[0003] This application claims priority to U.S. Patent Application No. 17 / 491,828 filed on October 1, 2021, the entirety of which is incorporated by reference herein. TECHNICAL FIELD

[0004] The present disclosure relates generally to cooling passages for engines, and more particularly, to a set of cooling passages for cooling a tip of an airfoil. BACKGROUND

[0005] Turbine engines, particularly gas or combustion turbine engines, are rotary engines that extract energy from a flow of combustion gases passing through the engine and flowing over a plurality of airfoils including stationary vanes and rotating turbine blades.

[0006] Gas turbine engines for aircraft are designed to operate at high temperatures to maximize engine efficiency, and thus it can be beneficial to cool certain engine components, such as the high pressure turbine and the low pressure turbine. Typically, cooling is accomplished by ducting cooler air from the high pressure and / or low pressure compressors to the engine components that require cooling. The temperatures in the high pressure turbine are on the order of 1000°C to 2000°C, and the cooling air from the compressors is on the order of 500°C to 700°C. While the compressor air is high temperature, it is cooler relative to the turbine air and can be used to cool the turbine.

[0007] Modern turbine blades and other engine components generally include one or more internal cooling circuits for directing cooling air through the engine component to cool different portions of the engine component, and can include dedicated cooling circuits for cooling different portions of the engine component. BRIEF DESCRIPTION OF DRAWINGS

[0008] In the description of the specification with reference to the drawings, the complete and enabling disclosure is set forth, including its best mode, for one of ordinary skill in the art to make and use, wherein:

[0009] Figure 1 is a schematic cross-sectional view of a gas turbine engine for an aircraft.

[0010] Figure 2 is a perspective view of an exemplary airfoil of the engine of Figure 1 is a perspective view of an exemplary airfoil of the engine of

[0011] Figure 3 is Figure 2 an enlarged perspective view of a tip of an airfoil showing multiple sets of cooling passages that are discharged into each of two tip edges.

[0012] Figure 4 is an enlarged perspective view of a tip of an airfoil similar to that of Figure 2 showing multiple sets of cooling passages that are discharged into a third tip edge and onto the outside of the airfoil and onto the upper surface of the tip rail of the airfoil.

[0013] Figure 5 is an enlarged view of an exemplary cooling passage from Figure 4 .

[0014] Figure 6 is a cross-sectional view of a cooling passage 134a from Figure 3 according to an aspect disclosed herein.

[0015] Figure 7A is a cross-sectional view of a cooling passage 134b from Figure 3 according to another aspect disclosed herein.

[0016] Figure 7B is a cross-sectional view of a variation of a cooling passage 134b from Figure 3 according to another aspect disclosed herein.

[0017] Figure 8 is a cross-sectional view of a cooling passage 134c from Figure 4 according to another aspect disclosed herein.

[0018] Figure 9 is a cross-sectional view of a cooling passage 134d from Figure 4 according to yet another aspect disclosed herein.

[0019] Figure 10 is a cross-sectional view of a cooling passage 134e from Figure 4 according to yet another aspect disclosed herein.

[0020] Figure 11 is a cross-sectional view along line XI-XI of Figure 12 showing flow enhancement according to an aspect disclosed herein.

[0021] Figure 3 is a flowchart showing a method of cooling an airfoil with a set of cooling passages of Figure 1 . DETAILED DESCRIPTION

[0022] The disclosed aspects described herein are directed to the geometry of a diffusion slot of at least one cooling passage of a set of cooling passages. More specifically, the diffusion slot terminates into an opening onto an outer surface of a wall of an engine component, which in one non-limiting example is an airfoil. For illustrative purposes, the disclosure will be described with respect to a turbine for an aircraft gas turbine engine. However, it will be understood that the aspects of the disclosure described herein are not so limited and can have universal applicability to engines including compressors and in non-aircraft applications such as other mobile applications and non-mobile industrial, commercial, and residential applications.

[0023] As used herein, the term "upstream" refers to a direction opposite to that of fluid flow, while the term "downstream" refers to a direction the same as that of fluid flow. The term "forward" or "forwardly" means in front of something, and "aft" or "aftly" means behind something. For example, when used in relation to fluid flow, forward / forwardly can mean upstream, and aft / aftly can mean downstream.

[0024] Additionally, as used herein, the term "radial" or "radially" refers to a direction away from a common center. For example, in the overall context of a turbine engine, radial refers to a direction along a ray extending between a central longitudinal axis of the engine and an outer periphery of the engine. Further, as used herein, the term "set" or "set" of elements can be any number of elements, including only one. The term "predetermined" as used herein relates to a value that has been calculated for peak performance in the environment in which the component resides.

[0025] All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, aft, etc.) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the disclosed aspects described herein. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and will be given their ordinary and accustomed meaning to

[0026] Figure 1is a schematic cross-sectional view of a gas turbine engine 10 for an aircraft. The engine 10 has a generally longitudinally extending axis or centerline 12 extending from a forward end 14 to an aft end 16. The engine 10 includes, in downstream serial flow relationship: a fan section 18 including a fan 20, a compressor section 22 including a booster or low pressure (LP) compressor 24 and a high pressure (HP) compressor 26, a combustion section 28 including a combustor 30, a turbine section 32 including a HP turbine 34 and a LP turbine 36, and an exhaust section 38.

[0027] The fan section 18 includes a fan casing 40 surrounding the fan 20. The fan 20 includes a plurality of fan blades 42 disposed radially about the centerline 12. The HP compressor 26, the combustor 30, and the HP turbine 34 form a core 44 of the engine 10 that generates combustion gases. The core 44 is surrounded by a core casing 46, which can be coupled with the fan casing 40.

[0028] A HP shaft or spool 48 coaxially disposed about the centerline 12 of the engine 10 drivingly connects the HP turbine 34 to the HP compressor 26. A LP shaft or spool 50 coaxially disposed about the centerline 12 of the engine 10 within the larger diameter annular HP spool 48 drivingly connects the LP turbine 36 to the LP compressor 24 and the fan 20. The spools 48, 50 are rotatable about the engine centerline and are coupled to a plurality of rotatable elements that can collectively define a rotor 51.

[0029] The LP compressor 24 and the HP compressor 26 each include a plurality of compressor stages 52, 54 in which a set of compressor blades 56, 58 rotate relative to a corresponding set of stationary compressor vane 60, 62 to compress or pressurize a fluid flow passing through the stage. In a single compressor stage 52, 54, the plurality of compressor blades 56, 58 can be disposed in a ring and can extend radially outward from a blade platform to a blade tip relative to the centerline 12, while the corresponding stationary compressor vane 60, 62 is positioned upstream of and adjacent to the rotating blades 56, 58. Notably, Figure 1 The number of blades, vanes, and compressor stages shown in FIG. 1 is selected for illustrative purposes only, and other numbers are possible.

[0030] The blades 56, 58 for a stage of the compressor can be mounted to (or integrated with) a disk 61 that is mounted to a corresponding one of the HP spool 48 and the LP spool 50. The vanes 60, 62 for a stage of the compressor can be mounted to the core casing 46 in a circumferential arrangement.

[0031] The HP turbine 34 and the LP turbine 36 each include a plurality of turbine stages 64, 66 with a set of turbine blades 68, 70 rotating relative to a corresponding set of static turbine vanes 72, 74 (also referred to as nozzles) to extract energy from a fluid flow passing through the stage. In a single turbine stage 64, 66, the plurality of turbine blades 68, 70 can be arranged in a ring and can extend radially outward relative to the centerline 12, while the corresponding static turbine vanes 72, 74 are positioned upstream of and adjacent to the rotating turbine blades 68, 70. Notably, Figure 2 The number of blades, vanes, and turbine stages shown in FIG. 6 is chosen for purposes of illustration only, and other numbers are possible.

[0032] The turbine blades 68, 70 for a stage of the turbine can be mounted to a disk 71 mounted to a corresponding one of the HP spool 48 and the LP spool 50. The static turbine vanes 72, 74 for a stage of the compressor can be mounted to the core casing 46 in a circumferential arrangement.

[0033] In addition to the rotor portion, the stationary portion of the engine 10, such as the static turbine vanes 60, 62, 72, 74 among the compressor section 22 and the turbine section 32, are also referred to individually or collectively as a stator 63. Thus, the stator 63 can refer to the combination of non-rotating elements in the entire engine 10.

[0034] In operation, the airflow exiting the fan section 18 is split so that a portion of the airflow is directed into the LP compressor 24, which then supplies pressurized air 76 to the HP compressor 26, which further pressurizes the air. The pressurized air 76 from the HP compressor 26 is mixed with fuel in the combustor 30 and ignited, generating combustion gases. The HP turbine 34 extracts some work from these gases, driving the HP compressor 26. The combustion gases are discharged into the LP turbine 36, which extracts additional work to drive the LP compressor 24, and the exhaust gases are ultimately discharged from the engine 10 via the exhaust section 38. The driving of the LP turbine 36 drives the LP spool 50 to rotate the fan 20 and the LP compressor 24.

[0035] A portion of the pressurized airflow 76 can be extracted from the compressor section 22 as bleed air 77. The bleed air 77 can be extracted from the pressurized airflow 76 and provided to engine components that require cooling. The temperature of the pressurized airflow 76 entering the combustor 30 is significantly increased above the bleed air temperature. The bleed air 77 can be used to reduce the temperature of core components downstream of the combustor.

[0036] The remaining portion 78 of the airflow bypasses the LP compressor 24 and engine core 44 and exits the engine 10 at a fan exhaust side 84 through a stationary vane row, more specifically, through an outlet guide vane assembly 80 including a plurality of airfoil guide vanes 82. More specifically, a circumferential row of radially extending airfoil guide vanes 82 are used near the fan section 18 to impart some directional control to the airflow 78.

[0037] Some air supplied by the fan 20 can bypass the engine core 44 and be used to cool portions of the engine 10, particularly hot portions of the engine 10, and / or to cool or power other aspects of the aircraft. In the context of a turbine engine, the hot portions of the engine are generally downstream of the combustor 30, particularly the turbine section 32, with the HP turbine 34 being the hottest portion as it is directly downstream of the combustion section 28. Other sources of cooling fluid can be, but are not limited to, fluid bled from the LP compressor 24 or the HP compressor 26.

[0038] Reference is now made to Figure 1 , which shows an engine component in the form of a turbine vane 68 from the engine 10 of Figure 1 . Alternatively, the engine component can be a vane, strut, service pipe, shroud, or combustion liner, or can be any other engine component that can require or use a cooling passage, in non-limiting examples. The turbine vane 68 includes a dovetail 90 and an airfoil 92. The dovetail 90 further includes at least one inlet passage 100, shown as three exemplary inlet passages 100, each inlet passage 100 extending through the dovetail 90 to provide internal fluid communication with the airfoil 92 at a supply outlet 102. It will be appreciated that the dovetail 90 is shown in cross-section such that the inlet passages 100 are housed within the body of the dovetail 90. For example, the dovetail 90 can be configured to be mounted to a turbine rotor disk 71 of the engine 10 of Figure 3 .

[0039] The airfoil 92 can extend radially between a tip 94 and a root 96, defining a spanwise direction therebetween. The airfoil 92 is mounted to the dovetail 90 at a platform 98 at the root 96. The platform 98 helps to radially contain the turbine engine main flow stream. Additionally, the airfoil 92 can include an outer wall 104 having a first side 106 and a second side 108, and extending between a leading edge 110 and a trailing edge 112 to define a streamwise direction therebetween. It should be appreciated that the upstream edge 110 can be a leading edge of the airfoil 92, and the downstream edge 112 can be a trailing edge of the airfoil 92. Further, as shown, the first side 106 can be a pressure side of the rotating vane, and the second side 108 can be a suction side of the rotating vane. Still further contemplated is that the airfoil 92 can be a non-rotating vane, such as a frame fairing, as non-limiting examples. Still further contemplated is that neither the first side 106 nor the second side 108 is curved to form a pressure side and / or a suction side. The outer wall 104 can partially define and surround at least one cooling conduit 114, shown as two exemplary cooling conduits 114 forming a cooling circuit 116.

[0040] An interior 118 defined by the outer wall 104 can be closed at the tip 94 by a tip wall 120. A tip rail 122 or groove defining a substantially continuous wall can extend outwardly from and around a perimeter of the tip wall 120 to at least partially bound an area defining a plenum 124.

[0041] At least one tip rim 126 can be formed in the outer wall 104. The at least one tip rim 126 as described herein can be defined as an edge formed by a region of an outer surface. As a non-limiting example, the outer wall 104 or a tip rail surface 128 proximate the tip 94 is removed or cut away for a cooling passage 134 described herein to discharge a cooling fluid (C). A first tip rim 126a can be formed in the outer wall 104 at the tip rail 122 on the first side 106. A second tip rim 126b can be formed in the tip rail 122 facing the plenum 124. The second tip rim 126b can be located between the tip wall 120 and an upper tip rail surface 132. The tip rim 126b can be a shelf 148 Figure 3 extending out from the tip wall 120 as a protrusion to or into the tip wall 120. It is contemplated that the tip rim 126 can be formed on any portion of the tip rail 122, as well as along the second side 108 of the tip rail 122 that is obscured in the perspective view. Unless otherwise noted, references herein to the tip rim 126 refer to any tip rim, including but not limited to the first tip rim 126a and the second tip rim 126b.

[0042] In operation, a hot gas stream (H g ) such as a combustor flow can pass along the exterior of the outer wall 104 of the airfoil 92 to define a heating surface. A cooling fluid stream (C) can be provided to the inlet passage 100 and into the airfoil 92 at the supply outlet 102, into at least one cooling conduit 114. The cooling fluid stream (C) can be provided throughout the cooling circuit 116 and discharged at the tip edge 126 as a cooling film. Any surface facing the cooling fluid stream (C) can be defined as a cooling surface.

[0043] Figure 3 is an enlarged perspective view at the tip 94 of the airfoil 92. The tip rail 122 projects from the tip wall 120 and has an inner tip rail surface 128 facing the plenum 124. An outer tip rail surface 130 can extend from at least one of the first side 106 and the second side 108. In other words, the outer tip rail surface 130 can be in the same plane as the exterior of the outer wall 104. The outer tip rail surface 130 can be spaced apart from the inner tip rail surface 128 to define a tip rail thickness (T). The tip rail 122 can terminate radially in an upper tip rail surface 132. The upper tip rail surface 132 can connect the inner tip rail surface 128 and the outer tip rail surface 130.

[0044] A cavity 133 can be located in the tip rail 122 and spaced apart from the upper tip rail surface 132 by a predetermined height dimension (H). A portion of the cavity 133 can define the tip edge 126. In other words, the tip edge 126 can be defined as where the cavity 133 intersects the outer wall 104. The tip edge 126 can begin downstream of the upstream edge 110 at a location spaced apart from the upstream edge 110 by a predetermined width dimension (W). The cavity 133 can have an opening (O) in the outer wall 104 or the inner tip rail surface 128 of a predetermined dimension. The cavity 133 can extend in the streamwise direction to define a slot outlet 142. The slot outlet 142 can extend between the upstream edge 110 and the downstream edge 112. The slot outlet 142 can terminate in a rim wall 146 that extends both toward the downstream edge 112 and the upper tip rail surface 132. In other words, the rim wall 146 can be angled relative to the streamwise direction. It is further contemplated that the rim wall 146 extends vertically in the spanwise direction.

[0045] A set of cooling passages 134 can discharge at the tip 94. The set of cooling passages 134 can define at least a portion of various cooling holes, by way of non-limiting example, in-line diffusers, diffuser slots, jet holes, and trailing edge jet holes. The sets of cooling passages 134 as described herein can be a single cooling passage or a plurality of cooling passages. The set of cooling passages 134 can be two sets of cooling passages, a first set of cooling passages 134a discharging on the first side 106, and a second set of cooling passages 134b discharging into the plenum 124. Further, the set of cooling passages 134 can be arranged in a streamwise arrangement. Optionally, another set of cooling passages can be provided on the second side 108, but is obscured from view. Unless otherwise noted, reference herein to a set of cooling passages 134 refers to any of the sets of cooling passages 134, including but not limited to the first set of cooling passages 134a and the second set of cooling passages 134b. Figure 5

[0046] The first set of cooling passages 134a can include a plurality of cooling passages 136, by way of non-limiting example, seven cooling passages 136 as shown. At least one cooling passage 136 can include a diffuser slot 138 opening at a passage exit 140 to the first tip edge 126a. The diffuser slot 138 can be fluidly coupled to the at least one cooling conduit 114 via an intermediate exit 139, also shown in phantom. Each diffuser slot 138 can define a diffuser vector (V) extending along a slot centerline (CL) toward the passage exit 140. The corresponding diffuser vector (V) of each cooling passage of the plurality of cooling passages 136 progressively points toward the downstream edge 112, moving from the upstream edge 110 toward the downstream edge 112. Figure 4

[0047] The plurality of passage exits 140 can merge together to form a slot exit 142. The slot exit 142 can define the entire first tip edge 126a. The slot exit 142 can open upwardly to the cavity 133. Thus, the first tip edge 126a can be an edge or rim of the outer wall 104 that terminates at the cavity 133. The second set of cooling passages 134b can include a plurality of cooling passages 136, by way of non-limiting example, four cooling passages 136 as shown. At least one cooling passage 136 can include a diffuser slot 138 opening at a passage exit 140 to the slot exit 142.

[0048] It is also contemplated that the plurality of passage exits 140 can be spaced apart from one another to define a shelf 148 therebetween. The shelf 148 can extend into the inner tip surface 128 or away from the inner tip surface 128.

[0049] Figure 5 ​​is an enlarged perspective view of a variation of the tip 94 of the airfoil 92 according to another aspect disclosed herein. A third tip edge 126c can be formed in the outer wall 104 at the tip rail 122 on the first side 106. The third tip edge 126c can include at least one or all of the trench outlet 142, the rim wall 146, and the shelf 148 as described herein. Further, the third tip edge 126c can extend between the upstream rim 110 and the downstream rim 112 and begin downstream of the upstream rim 110 at a location spaced apart from the upstream rim 110 by a predetermined width dimension (W). Additionally, the third tip edge 126c can define a predetermined cutout dimension (D) that extends all the way to the upper tip rail surface 132. In this way, the third tip edge 126c is a top open cutout 150, which is different from the cavity 133 described previously herein. The rim wall 146 can also terminate at the upper tip rail surface 132.

[0050] In this variation of the tip 94, a third, fourth, and fifth set of cooling passages 134c, 134d, 134e are shown. The third set of cooling passages 134c can include at least one cooling passage 136 with a diffusion slot 138 opening to the third tip edge 126c at a passage outlet 140. The passage outlets 140 can be spaced apart in the streamwise direction to define the shelf 148 as described previously herein. The third set of cooling passages 134c can include a plurality of cooling passages 136, as a non-limiting example, four cooling passages 136 as shown.

[0051] The fourth set of cooling passages 134d can include at least one cooling passage 136 with a diffusion slot 138 opening to the upper tip rail surface 132 at a passage outlet 140. The fourth set of cooling passages 134d can include a plurality of cooling passages 136, as a non-limiting example, three cooling passages 136 as shown.

[0052] The fifth set of cooling passages 134e can include at least one cooling passage 136 with a diffusion slot 138 opening to the outer wall 104 along the first side 106 at a passage outlet 140. The fifth set of cooling passages 134e can include a plurality of cooling passages 136, as a non-limiting example, two cooling passages 136 as shown.

[0053] Each of the sets of cooling passages 134 described herein can include a plurality of cooling passages 136, each cooling passage having a corresponding diffusion slot 138, the corresponding diffusion slot 138 having a corresponding passage outlet 140. The diffusion slots 138 can be fluidly coupled to the at least one cooling conduit 114 via an intermediate outlet 139, also shown in phantom. In some embodiments, the diffusion slots 138 can be angled toward the upstream rim 110 or toward the downstream rim 112 or anywhere in between.

[0054] Each diffusion slot 138 can define a diffuser vector (V) as described herein. As shown, the corresponding diffuser vector (V) for each cooling passage 136 of the plurality of cooling passages 136 can be directed toward the upstream edge 110, the upper tip rail surface 132, or the downstream edge 112. In other words, the diffusion slots 138 can be arranged in a fan layout from a forward-facing position proximate the upstream edge 110, toward the intermediate upper tip rail surface 132, and a rear-facing position proximate the downstream edge 112.

[0055] Figure 6 is an exemplary enlarged view of one of the cooling passages 136. As a non-limiting example, the cooling passage 136 is from the set of cooling passages 134c. As a non-limiting example, to more clearly illustrate how the diffusion slots 138 can be angled toward the leading edge 110, two orientations are shown in phantom, a radial orientation 154 and an angled orientation 156.

[0056] The diffusion slot 138 extends between a rear portion 164 and a forward portion 166. The magnitude of the diffuser vector (V) can vary across the extent or length of the diffusion slot 138 between the rear portion 164 and the forward portion 166. The intermediate outlet 139 can define a diameter (D). It should be understood that if the intermediate outlet 139 is a non-circular shape, the diameter (D) is the diameter of a circular cross-sectional area that has the same area as the non-circular shape. The intermediate outlet 139 can be located proximate the rear portion 164, as “proximate” is used herein to mean within 0 and 50 diameters (D). The intermediate outlet 139 can be spaced apart from the rear portion 164 between 0 and 5D (zero to five times the diameter (D)). The diffusion slot 138 can define a slot centerline (CL) extending between an intermediate center 168 of the intermediate outlet 139 and an outlet center 170 of the passage outlet 140. While shown as having a circular shape, it should be understood that the intermediate outlet 139 can have any shape and still define a geometric center. The diffusion slot 138 can define an increasing cross-sectional area (CA) along the slot centerline (CL) extending from the rear portion 164 toward the passage outlet 140. It is contemplated that the slot centerline (CL) can be aligned with a radial direction (R) as shown in the radial orientation 154. It is further contemplated that the slot centerline (CL) can form a first angle Θ with the radial direction (R) between + / - 70°, such that the diffusion slot 138 is directed toward the leading edge 110 and / or the trailing edge 112.

[0057] The diffusion slot 138 can define a diffusion section 152. The diffusion section 152, and more specifically the geometry of the diffusion slot 138, enables the cooling fluid (C) to expand to form a wider and slower cooling film onto the exterior 172 of the airfoil 92, as a non-limiting example, onto the outer tip rail surface 130.

[0058] Figure 3 is an enlarged view of the diffusion slot 138 in the radial orientation 154.Figure 7A FIG. 16 is a cross-sectional view of the cooling passage 136 from the first set of cooling passages 134a taken along the line VI-VI. The cooling passage 136 can include a passage outlet to the first tip edge 126a. In an aspect disclosed herein, the first tip edge 126a can be infinitesimally small, zero, or extend into the airfoil some measurable amount as shown. It is further contemplated that the first tip edge 126a is a filleted tip edge 126f defining a rounded edge shown in dashed line at the passage outlet 140. It should be understood that the tip edge 126 as described herein can be a filleted tip edge 126f in any aspect.

[0059] The cooling passage 136 can include a first passage 174 to fluidly couple the diffusion slot 138 to the at least one cooling conduit 114 via the intermediate outlet 139. The first passage 174 can have a circular cross-section, although it can have any cross-sectional shape. The first passage 174 can extend along a first centerline (CL1) between an inlet 176 fluidly coupled to the at least one cooling conduit 114 and the intermediate outlet 139. The first centerline (CL1) can form a second angle a between 40 to 140 degrees, where the slot centerline (CL) at the junction 160 of the first passage 174 and the diffusion slot 138. It is further contemplated that the second angle a is substantially orthogonal or 90 degrees.

[0060] The first passage 174 can define a metering section 178. The metering section 178 can be defined as the smallest or minimum cross-sectional area of the first passage 174. The metering section 178 can extend along the first centerline (CL1) between the inlet 176 and the intermediate outlet 139 having a diameter (D). It is also contemplated that the metering section 178 has no length and is located at any portion of the cooling passage 136 where the cross-sectional area is the smallest. It is further contemplated that the inlet 176 defines the metering section 178 without any extension into the cooling passage 136. The cooling passage 136 as described herein can include multiple metering sections and is not limited to one as shown. The metering section 178 is used to meter the mass flow rate of the cooling fluid flow (C).

[0061] The middle outlet 139 of the first passage 174 can be spaced apart from the aft portion 164 to define a pocket 180. An impingement surface 182 can be located opposite the middle outlet 139 at the junction 160. The impingement surface 182 can define a portion of the diffusion slot 138. The impingement surface 182 can be located below the first tip edge 126a in the spanwise direction. Further, the passage outlet 140 can be located above the tip 94 in the spanwise direction, or radially outward of the tip wall 120. It is contemplated that the impingement surface 182 is parallel to the outer wall 104. As the diffusion slot 138 extends toward the upper tip rail surface 132, the proximity of the outer portion 172 of the outer wall 104 to the cooling passage 136 can decrease. In other words, the aft portion 164 of the diffusion slot 138 can be spaced inwardly from the outer portion 172, while the forward portion 166 can be located on the first tip edge 126a, proximate the outer portion 172.

[0062] Other geometric layouts of the cooling passage 136 are contemplated and shown in phantom. The cooling passage 136 can have a first passage 174a and a middle passage 174b fluidly connecting the first passage 174a to the diffusion slot 138, rather than primarily extending in the spanwise direction, with a single junction 160 between the first passage 174 and the diffusion slot 138. The first passage 174a can extend between an inlet 176a fluidly coupled to the at least one cooling conduit 114 and a first middle outlet 139a. The middle passage 174b can extend between the first middle outlet 139a and a second middle outlet 139b, where the middle passage 174b can be fluidly coupled to the diffusion slot 138. As shown, the middle passage 174b can extend substantially parallel to the tip wall 120. Either the first passage 174a or the middle passage 174b, or both the first passage 174a and the middle passage 174b, can define a metering section 178 as described herein. Further, additional pockets 180a, 180b, also shown in phantom, can be incorporated proximate additional junctions 160a, 160b as described herein. It is also contemplated that either of the additional pockets 180a, 180b are not incorporated, but rather an impingement surface as described herein is present. It is further contemplated that the cooling passage 136 is non-linear, as shown.

[0063] It is understood that while illustrated as having sharp corners and edges, the cavity 133 can have an aerodynamic geometry 133a having more rounded lines, shown in phantom. Depending on the implementation of the set of cooling passages 134a, the aerodynamic geometry 133a can facilitate increased laminar flow of the cooling fluid flow (C). In other implementations, the cavity 133 having sharp edges can provide impingement flow and turbulent flow, as shown. Both geometries are contemplated for all of the sets of cooling passages 134a, 134b, 134c, 134d, and 134e described herein.

[0064] During operation, the cooling fluid flow (C) can enter the cooling channel 136 and impact the impact surface 182. Furthermore, the cooling fluid flow (C) can rotate at the junction 160. This rotation causes dust particles that cannot rotate due to inertia to be collected in the bag portion 180, helping to maintain unobstructed cooling channel 136. The cooling fluid flow (C) can be discharged into cavity 133 and onto the first tip edge 126a, cooling the outer tip track surface 130 with a cooling film that detaches from or leaves cavity 133.

[0065] Figure 3 It is along Figure 7B The image shows a cross-sectional view of the cooling channel 136 from the second set of cooling channels 134b, taken along line VII-VII. The cooling channel 136 may include a channel outlet 140 near the opening of the second tip edge 126b. In the aspects disclosed herein, the second tip edge 126b may be infinitesimally small, or, as shown, extend a measurable amount away from the inner tip track surface 128 into the air chamber 124 to define the shelf 148. The second tip edge 126b may be a protrusion extending radially from the tip wall 120 into the air chamber 124. Thus, the second set of cooling channels 134b can cool the inner tip track surface 128 and the air chamber 124. Other features are similar to those already discussed herein.

[0066] Figure 3 It is along Figure 8 The image shows a modified cross-sectional view of the cooling channel 136 from the second set of cooling channels 134b, taken along line VII-VII. The cooling channel 136 may include a channel outlet 140 leading to the cavity 133. In the aspects disclosed herein, the second tip edge 126b may be infinitesimally small, or, as shown, extend into the cavity 133 by some measurable amount, beyond the inner tip track surface 128, to define the shelf 148. Thus, the second set of cooling channels 134b can cool the inner tip track surface 128 and the air chamber 124. Other features are similar to those already discussed herein.

[0067] Figure 4 It is along Figure 9 The image shows a cross-sectional view of cooling channel 136 from the second set of cooling channels 134c, taken by line VIII-VIII. Cooling channel 136 may include a channel outlet 140 leading to a third tip edge 126c. In the aspects disclosed herein, the third tip edge 126c may be infinitesimally small, or, as shown, extend to some measurable amount within the airfoil. Thus, the third set of cooling channels 134c can cool the outer tip track surface 130. Other features are similar to those already discussed herein.

[0068] Figure 4 It is alongFigure 10 is a cross-sectional view of a cooling passage 136 from the fourth set of cooling passages 134d taken along line IX-IX. The cooling passage 136 can include a passage exit 140 to the upper tip rail surface 132 of the tip rail 122. Thus, the fourth set of cooling passages 134d can cool the upper tip rail surface 132. Other features are similar to those already discussed herein.

[0069] Figure 4 is a cross-sectional view of a cooling passage 136 from the fifth set of cooling passages 134e taken along line X-X. The cooling passage 136 can include a passage exit 140 to the outer tip rail surface 130 of the tip rail 122 along the outer wall 104. Thus, the fifth set of cooling passages 134d can cool the outer tip rail surface 122. Other features are similar to those already discussed herein. Figure 11

[0070] Figure 12 is a view of any one of the sets of cooling passages 134 described herein, as a non-limiting example, the fifth set of cooling passages 134d. It is contemplated that any one of the sets of cooling passages 134 as described herein can include a set of flow enhancers 184, as a non-limiting example, full height heat transfer coefficient (HTC) enhancement features such as pins, or partial height HTC enhancement features such as turbulators, bumps, dimples, etc. Higher HTC results in increased cooling of the outer wall 104 and increased temperature of the cooling fluid (C). By placing the HTC enhancement features, a balance can be achieved where the cooling benefit in one area outweighs the temperature increase of the cooling fluid (C).

[0071] ​ is a flowchart illustrating a method 200 for cooling the airfoil 92. The method 200 includes receiving a cooling fluid flow (C) at 202 at an inlet 176 of a cooling passage 136. At 204, the cooling fluid flow (C) is flowed into a diffusion slot 138. The method can include impinging the cooling fluid flow (C) on an impingement surface 182, and diverting the cooling fluid flow (C) from a first passage 174 to the diffusion slot 138. The method can further include directing the cooling fluid flow (C) in a radial direction (R) toward the tip rail 122 at 206. At 208, the cooling fluid flow (C) is expanded in a direction perpendicular to the radial direction (R), as a non-limiting example, in a streamwise direction or a primarily axial direction. The method can include emitting the cooling fluid flow (C) along an outer surface 172 of the tip rail 122 at 210.

[0072] ​The method 200 can further include emitting the cooling fluid flow (C) specifically along the tip edge 126. The cooling fluid flow (C) can form a film along any portion of the tip rail 122. It is further contemplated that the method 200 can include emitting the cooling fluid flow toward one of the downstream edge 112 or the upstream edge 110 of the airfoil 92.

[0073] Benefits associated with the disclosures described herein include increased cooling efficiency, which results in increased hot gas path durability (which in turn reduces maintenance costs) and better specific fuel consumption (SFC). Additionally, the geometry and location of the cooling passages as described herein improve film efficiency in protecting the tip of the airfoil and places impingement near the tip, which is a highly efficient internal cooling mechanism.

[0074] Impingement and the immediate expansion of the cooling fluid within the diffusion slot facilitates high convection near the tip and tip rail. Additionally, the introduction of the cooling fluid via the metering passage and then the emission of the cooling fluid near or along the tip surface increases film cooling efficiency.

[0075] The cooling passages as described herein can be produced by additive manufacturing techniques and advanced casting manufacturing techniques. It should be understood that the application of the disclosed designs is not limited to turbine engines having fan and booster sections, but also applies to turbojet and turbocharged engines.

[0076] The second cooling passage portion as described herein can also include a bend defining a turn prior to the junction. Further, while the walls of the engine components described herein are illustrated as being generally straight, with the inner and outer surfaces parallel to each other, the engine components or airfoils described herein can be curved and oriented at an angle relative to the combustion flow. While illustrated as generally uniform or continuously widening, the passage cross-sections as described herein can allow for variation in collapse, widening, etc. in both directions. The variation can be non-linear, non-constant, etc.

[0077] The set of cooling passages as described herein can include at least two cooling passages having surface outlets that merge together to form a trench. It is further contemplated that all of the cooling passages in the set of cooling passages have surface outlets that merge together to form a trench. The trench can extend radially along the airfoil.

[0078] It should be appreciated that cooling passages as described herein can be provided in any portion of an airfoil or engine component. Further, it should be appreciated that, for example, cooling passages as described herein can have additional applicability to other portions of an airfoil, such as a leading edge, a trailing edge, a pressure side, a suction side, a tip, a root, or even internal structures of an airfoil. Still further, in non-limiting examples, cooling hole geometries can have applicability in other engine components besides airfoils, such as vanes, blades, struts, shrouds, or combustor liners.

[0079] Cooling passages and other complex geometries as described herein can be formed, for example, by additive manufacturing, while also being contemplated for traditional manufacturing methods. Additive manufacturing (AM) processes build parts layer by layer through successive deposition of material. AM is the apt name for the technology that builds 3D objects by adding layer upon layer of material, whether plastic or metal. AM technology can use computers, 3D modeling software (computer-aided design or CAD), machine equipment, and layered materials. Once a CAD sketch is produced, the AM equipment can read the data from the CAD file and place or add successive layers of liquid, powder, sheet, or other material in layer upon layer fashion to manufacture the 3D object. It should be appreciated that the term "additive manufacturing" encompasses a number of technologies, including subsets such as 3D printing, rapid prototyping (RP), direct digital manufacturing (DDM), layer additive manufacturing, and additive manufacturing. Non-limiting examples of additive manufacturing that can be used to form additive manufactured parts include powder bed fusion, vat photopolymerization, binder jetting, material extrusion, directed energy deposition, material jetting, or sheet lamination. Additive manufacturing such as 3D printing, direct metal laser melting, direct metal laser sintering, or electroforming can provide for the formation of complex geometries as described herein that can be challenging, expensive, or time-consuming, and low yielding, through traditional manufacturing means such as casting or drilling. Further, cooling passages described herein can be produced via indirect additive methods, i.e., printing a core and casting, or a core can also be made via additive manufacturing core, or via RMC.

[0080] It should be appreciated that the application of the disclosed design is not limited to turbine engines having fan and booster sections, but is also applicable to turbojet engines and turbine engines.

[0081] Various features and aspects of the different aspects can be used in combination or substituted for each other as needed within the scope of the description. The failure to exemplify one feature in an example does not mean it cannot be so exemplified, but rather it is done for descriptive brevity. Thus, various features of the different aspects can be mixed and matched to form new aspects, whether or not those new aspects are expressly described. All combinations or permutations of every feature described herein are covered by this disclosure.

[0082] This written description uses examples to describe the aspects of the disclosure described herein, including the best mode, and also to enable any person skilled in the art to practice the aspects of the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the aspects of the disclosure is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent

[0083] Further aspects of the disclosure are provided by the subject matter of the following clauses:

[0084] An engine component for a turbine engine having a working airflow that is separated into a cooling airflow and a combustion airflow, the engine component comprising: a wall defining an interior and having an outer surface through which the combustion airflow flows, the outer surface defining a first side and a second side, the first and second sides extending between an upstream edge and a downstream edge to define a streamwise direction and between a root and a tip to define a radial direction; a tip wall spanning the first and second sides to enclose the interior at the tip; a tip rail extending from the tip wall and having an inner tip rail surface that, in combination with the tip wall, at least partially bounds an area defining a plenum, the tip rail having an outer tip rail surface extending from at least one of the first and second sides and terminating radially in an upper tip rail surface that connects the inner and outer tip rail surfaces; a tip rim formed in the outer wall in at least one of the first and second sides and spaced apart from the upper tip rail surface in the radial direction; at least one cooling conduit disposed in the interior; a set of cooling passages formed in the outer wall and fluidly coupling the at least one cooling conduit to the outer surface, at least one cooling passage of the set of cooling passages comprising: a diffusion slot extending in a flow direction toward the tip between a rear and a passage exit leading to the tip rim, the diffusion slot defining a slot centerline along which a diffuser vector extends between the rear and the passage exit; at least one metering passage having an inlet fluidly connected to the at least one cooling conduit and an intermediate outlet fluidly coupled to the diffusion slot at a junction proximate the rear of the diffusion slot and defining a first centerline that forms an angle relative to the slot centerline.

[0085] The engine component of any of the preceding clauses, wherein the tip rim is formed in the outer tip rail surface.

[0086] The engine component of any of the preceding clauses, wherein the tip rim terminates in a rim wall extending toward the downstream edge and the upper tip rail surface.

[0087] The engine component of any of the preceding clauses, wherein the rim wall terminates at the upper tip rail surface.

[0088] The engine component of any of the preceding clauses, further comprising a cavity extending in the streamwise direction and spaced apart from the tip, the cavity defining the tip rim.

[0089] The engine component of any of the preceding clauses, wherein at least one of the cavity and the tip rim comprises a circular geometry.

[0090] The engine component of any of the preceding clauses, wherein the tip rim is formed in the inner tip rail surface.

[0091] The engine component of any of the preceding clauses, wherein the tip rim is located between the tip wall and the upper tip rail surface.

[0092] The engine component of any of the preceding clauses, wherein the at least one cooling passage is a plurality of cooling passages extending between the upstream edge and the downstream edge.

[0093] The engine component of any of the preceding clauses, wherein the plurality of cooling passages have a diverging vector that gradually points toward the downstream edge as moving from the upstream edge to the downstream edge.

[0094] The engine component of any of the preceding clauses, wherein the intermediate outlet is spaced apart from the aft portion to define a pocket.

[0095] The engine component of any of the preceding clauses, wherein the at least one cooling passage is a plurality of cooling passages extending between the upstream edge and the downstream edge, and a diverging length varies among the plurality of cooling passages.

[0096] The engine component of any of the preceding clauses, wherein an increase in cross-sectional area along the flow direction is defined by a first angle.

[0097] The engine component of any of the preceding clauses, wherein the at least one cooling passage is a plurality of cooling passages extending between the upstream edge and the downstream edge, and the first angle varies among the plurality of cooling passages.

[0098] The engine component of any of the preceding clauses, further comprising a second set of cooling passages formed in the outer wall and fluidly coupling the at least one cooling conduit to the outer surface, at least one cooling passage of the second set of cooling passages comprising a diverging slot that increases a cross-sectional area in a flow direction toward the tip and terminates in a passage outlet to the upper tip rail surface.

[0099] The engine component of any of the preceding clauses, wherein an impingement surface is located across from the intermediate outlet along a portion of the diverging slot.

[0100] The engine component of any of the preceding paragraphs, further comprising a flow enhancement structure within the diffusion slot.

[0101] A method for cooling an airfoil extending between a root and a tip to define a radial direction and having a cooling passage, the method comprising: receiving a cooling fluid flow at an inlet of the cooling passage; flowing the cooling fluid flow through the cooling passage and into a diffusion slot; directing the cooling fluid flow in a primarily radial direction within the diffusion slot; expanding the cooling fluid flow within the diffusion slot in a direction perpendicular to the primarily radial direction; emitting the cooling fluid flow from the diffusion slot at a passage outlet opening along an outer surface of a tip rail of the airfoil.

[0102] The method of any of the preceding paragraphs, further comprising impinging the cooling fluid flow on an impingement surface within the cooling passage.

[0103] The method of any of the preceding paragraphs, further comprising diverting the cooling fluid flow from a first passage to the diffusion slot.

[0104] The method of any of the preceding paragraphs, wherein the expanding comprises expanding the cooling fluid flow in a streamwise direction.

[0105] The method of any of the preceding paragraphs, further comprising emitting the cooling fluid flow at a passage outlet opening along a tip edge in the tip rail.

[0106] The method of any of the preceding paragraphs, further comprising emitting the cooling fluid flow toward one of an upstream edge or a downstream edge of the airfoil.

Claims

1. An engine component for a turbine engine having a working airflow that is separated into a cooling airflow and a combustion airflow, characterized by, The engine component comprises: an outer wall defining an interior and having an outer surface through which the combustion gas flow flows, the outer surface defining a first side and a second side, the first side and the second side extending between an upstream edge and a downstream edge to define a streamwise direction and between a root and a tip to define a radial direction; a tip wall spanning the first side and the second side to enclose the interior at the tip; a tip rail extending from the tip wall and having an inner tip rail surface that, in combination with the tip wall, at least partially bounds an area defining a plenum, the tip rail having an outer tip rail surface extending from at least one of the first side and the second side and terminating radially in an upper tip rail surface that connects the inner tip rail surface and the outer tip rail surface; a tip rim formed in at least one of the outer surface or the inner tip rail surface and spaced apart from the upper tip rail surface in the radial direction; at least one cooling conduit disposed in the interior; a slot outlet defining at least a portion of the tip rim; and a plurality of cooling passages formed in the outer wall and fluidically coupling the at least one cooling conduit to the slot outlet, wherein the plurality of cooling passages terminate in respective passage outlets that merge together to form the slot outlet.

2. The engine component of claim 1, wherein, wherein the tip rim is formed in the outer tip rail surface.

3. The engine component of claim 2, wherein, wherein the tip rim terminates in a rim wall extending toward the downstream edge and the upper tip rail surface.

4. The engine component of claim 3, wherein, wherein the rim wall terminates at the upper tip rail surface.

5. The engine component of claim 3, wherein, further comprising a cavity extending in the streamwise direction and spaced apart from the tip, at least a portion of the cavity defining the tip rim.

6. The engine component of claim 5, wherein, wherein at least one of the cavity and the tip rim comprises a circular geometry.

7. The engine component of claim 1, wherein wherein the tip rim is formed in the inner tip rail surface.

8. The engine component of claim 6, wherein, wherein the tip rim is located between the tip wall and the upper tip rail surface.

9. The engine component of claim 1, wherein, wherein each cooling passage of the plurality of cooling passages comprises a diffusion slot extending in a flow direction toward the tip between a back and a respective passage outlet, the diffusion slot defining a slot centerline along which a diffuser vector extends between the back and the respective passage outlet.

10. The engine component of claim 9, wherein, wherein a diffuser length varies among the plurality of cooling passages. wherein the tip rim is formed in the outer tip rail surface. wherein the tip rim terminates in a rim wall extending toward the downstream edge and the upper tip rail surface. wherein the rim wall terminates at the upper tip rail surface. further comprising a cavity extending in the streamwise direction and spaced apart from the tip, at least a portion of the cavity defining the tip rim. wherein at least one of the cavity and the tip rim comprises a circular geometry. wherein the tip rim is formed in the inner tip rail surface. wherein the tip rim is located between the tip wall and the upper tip rail surface. wherein each cooling passage of the plurality of cooling passages comprises a diffusion slot extending in a flow direction toward the tip between a back and a respective passage outlet, the diffusion slot defining a slot centerline along which a diffuser vector extends between the back and the respective passage outlet. wherein a diffuser length varies among the plurality of cooling passages.

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