Turbine engines, and particularly gas or combustion turbine engines, are rotary engines that extract energy from a flow of combusted gases passing through the engine onto a multitude of turbine blades. Gas turbine engines have been used for land and nautical locomotion and power generation, but are most commonly used for aeronautical applications such as for aircraft, including helicopters. In aircraft, gas turbine engines are used for propulsion of the aircraft. In terrestrial applications, turbine engines are often used for power generation.
Gas turbine engines for aircraft are designed to operate at high temperatures to maximize engine efficiency, so cooling of certain engine components, such as the high pressure turbine and the low pressure turbine, can be necessary. Typically, cooling is accomplished by ducting cooler air from the high and/or low pressure compressors to the engine components which require cooling. Temperatures in the high pressure turbine are around 1000° C. to 2000° C. and the cooling air from the compressor is around 500° C. to 700° C. While the compressor air is a high temperature, it is cooler relative to the turbine air, and can be used to cool the turbine.
Typical film cooling comprises film hole inlet placements which are presently uncontrolled, or non-optimized. Thus, film effectiveness is often based upon arbitrary placements of inlets relative to one another or additional internal features, which do not sufficiently optimize the cooling air to cool necessary engine components.
In one aspect, an engine component for a gas turbine engine, which generates a hot combustion gas flow, and provides a cooling fluid flow, comprising a wall separating the hot combustion gas flow from the cooling fluid flow, having a hot surface along with the hot combustion gas flows in a hot flow path and a cooling surface facing the cooling air flow. The engine component further comprises multiple film holes in a pre-determined arrangement along the hot flow path, with each film hole having an inlet provided on the cooling surface, an outlet provided on the hot surface, and a passage connecting the inlet and the outlet. At least two adjacent inlets along the cooling surface have at least one of a different orientation relative to the cooling fluid flow or are non-aligned with each other.
In another aspect, an engine component for a gas turbine engine, which generates a hot combustion gas flow, and provides a cooling fluid flow, comprising a wall separating the hot combustion gas flow from the cooling fluid flow and having a hot surface along with the hot combustion gas flows in a hot flow path, and a cooling surface facing the cooling air flow. At least two adjacent film holes inlets arranged along the cooling surface and having at least one of a different orientation relative to the cooling fluid flow or are non-aligned with each other.
In the drawings:
The described embodiments of the present invention are directed to apparatuses, methods, and other devices related to routing airflow in a turbine engine. For purposes of illustration, the present invention will be described with respect to an aircraft gas turbine engine. It will be understood, however, that the invention is not so limited and can have general applicability in non-aircraft applications, such as other mobile applications and non-mobile industrial, commercial, and residential applications.
It should be further understood that for purposes of illustration, the present invention will be described with respect to an airfoil for a turbine blade of the turbine engine. It will be understood, however, that the invention is not limited to the turbine blade, and can comprise any airfoil structure, such as a compressor blade, a turbine or compressor vane, a fan blade, a strut, a shroud assembly, or a combustor liner or any other engine component requiring cooling in non-limiting examples. Furthermore, as described herein, the internal cooling passages or cooling surface for the engine component can comprise a smooth, turbulated, pin bank, mesh, trailing edge, leading edge, tip, micro-circuit, or endwall in non-limiting examples.
As used herein, the term “forward” or “upstream” refers to moving in a direction toward the engine inlet, or a component being relatively closer to the engine inlet as compared to another component. The term “aft” or “downstream” used in conjunction with “forward” or “upstream” refers to a direction toward the rear or outlet of the engine relative to the engine centerline.
Additionally, as used herein, the terms “radial” or “radially” refer to a dimension extending between a center longitudinal axis of the engine and an outer engine circumference.
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, aft, etc.) are only used for identification purposes to aid the reader's understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and can include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to one another. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto can vary.
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, which generates combustion gases. The core 44 is surrounded by core casing 46, which can be coupled with the fan casing 40.
A HP shaft or spool 48 disposed coaxially 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, which is disposed coaxially 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 fan 20. The portions of the engine 10 mounted to and rotating with either or both of the spools 48, 50 are referred to individually or collectively as a rotor 51.
The LP compressor 24 and the HP compressor 26 respectively include a plurality of compressor stages 52, 54, in which a set of compressor blades 58 rotate relative to a corresponding set of static compressor vanes 60, 62 (also called a nozzle) to compress or pressurize the stream of fluid passing through the stage. In a single compressor stage 52, 54, multiple compressor blades 56, 58 can be provided in a ring and can extend radially outwardly relative to the centerline 12, from a blade platform to a blade tip, while the corresponding static compressor vanes 60, 62 are positioned downstream of and adjacent to the rotating blades 56, 58. It is noted that the number of blades, vanes, and compressor stages shown in
The HP turbine 34 and the LP turbine 36 respectively include a plurality of turbine stages 64, 66, in which a set of turbine blades 68, 70 are rotated relative to a corresponding set of static turbine vanes 72, 74 (also called a nozzle) to extract energy from the stream of fluid passing through the stage. In a single turbine stage 64, 66, multiple turbine blades 68, 70 can be provided in a ring and can extend radially outwardly relative to the centerline 12, from a blade platform to a blade tip, while the corresponding static turbine vanes 72, 74 are positioned upstream of and adjacent to the rotating blades 68, 70. It is noted that the number of blades, vanes, and turbine stages shown in
In operation, the rotating fan 20 supplies ambient air to the LP compressor 24, which then supplies pressurized ambient air to the HP compressor 26, which further pressurizes the ambient air. The pressurized air from the HP compressor 26 is mixed with fuel in the combustor 30 and ignited, thereby generating combustion gases. Some work is extracted from these gases by the HP turbine 34, which drives 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 gas is 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.
Some of the ambient air supplied by the fan 20 can bypass the engine core 44 and be used for cooling of portions, especially hot portions, of the engine 10, and/or used to cool or power other aspects of the aircraft. In the context of a turbine engine, the hot portions of the engine are normally downstream of the combustor 30, especially 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 is not limited to, fluid discharged from the LP compressor 24 or the HP compressor 26.
One or more of the engine components of the engine 10 has a film-cooled wall in which various film hole embodiments disclosed further herein can be utilized. Some non-limiting examples of the engine component having a film-cooled wall can include the blades 68, 70, vanes or nozzles 72, 74, combustor deflector 76, combustor liner 78, or shroud assembly 80, described in
The airfoil 90 can further define an interior 104, such that a flow of cooling fluid can be provided through the inlet passages 100 and to the interior 104 of the airfoil 90. Thus, a flow of cooling fluid C can be fed through the inlet passages 100, exiting the outlets 102, and passing within the interior 104 of the airfoil. The flow of hot combustion gas H can pass external of the airfoil 90, while the cool airflow C moves within the interior 104.
The engine component 120 includes a wall 122 having a hot surface 126 facing the hot combustion gas H and a cooling surface 124 facing the cooling fluid flow C. In the case of a gas turbine engine, the hot surface 126 can be exposed to gases having temperatures in the range of 1000° C. to 2000° C. Suitable materials for the wall 122 include, but are not limited to, steel, refractory metals such as titanium, or super alloys based on nickel, cobalt, or iron, and ceramic matrix composites.
The engine component 120 can define the interior 104 of the airfoil 90 of
Referring to
Each film hole 130 can have an inlet 132 provided on the cooling surface 124 of the wall 122, an outlet 134 provided on the hot surface 126, and a passage 136 connecting the inlet 132 and outlet 134. During operation, the cooling fluid flow C enters the film hole 130 through the inlet 132 and passes through the passage 136 before exiting the film hole 130 at the outlet 134 along the hot surface 126.
The passage 136 can define a metering section for metering of the mass flow rate of the cooling fluid flow C. The metering section can be a portion of the passage 136 with the smallest cross-sectional area, and can be a discrete location or an elongated section of the passage 136. The passage 136 can further define a diffusing section in which the cooling fluid flow C can expand to form a wider cooling film. The metering section can be provided at or near the inlet 132, while the diffusion section can be defined at or near the outlet 134.
The film holes 130 can comprise multiple film holes 130 disposed along the wall 122 of the engine component 120. Each film hole inlet 132 can define a major axis 140. The circular shape of the inlet 132 can define an ellipse-shaped outlet, such that the axis can be defined between the vertices of the ellipse. Furthermore, two or more inlets 132 can be grouped or arranged together to define a film hole inlet arrangement 142. As exemplarily shown in
The arrangements 142 can define a pre-determined relationship between at least two adjacent film hole inlets 132. The pre-determined relationship defined by the arrangements 142 can comprise a relative orientation for the inlets 132, being relative to the flow of cooling fluid, another film hole inlet 132, or another arrangements 142 in non-limiting examples. It should be understood that the arrangements 142 can comprise pairs of adjacent inlets 132, multiple pairs of inlets 132, or of variable organizations of film holes 132 into the arrangements. Furthermore, as described herein, the pre-determined relationship can be defined by adjacent film holes relative to an axis defined by the inlet, such as a major axis. However, the axes need not be limited to the same angles, relative to one or more of the cooling fluid flow C, an axial direction, a radial direction, the angle of the passage 136, or any combination thereof. Thus, the angles or axes defined by the film holes 130 or the inlets 132 can be in a predetermined relationship to one another, without a limited orientation relative to one another.
It should be further understood that the round shape for the film holes 130 and the ellipse-shaped inlets 132 and outlets 134 are exemplary. Alternative film hole shapes as well as inlet and outlet shapes are contemplated, including but not limited to circle, oval, triangle, square quadrilateral, unique, or otherwise.
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It should be appreciated in further examples, the turbulator 202 of
It should be appreciated that while this description is generally described as having two inlets within each arrangement, any number of inlets can comprise an arrangement. Additionally, one or more inlets within each arrangement can be angularly offset from the direction of the flow of cooling fluid, as defined by the major axes of the inlets. Where inlets have different shapes than the elliptical shapes as illustrated, the major axis can be defined across the greatest cross-sectional distance as defined by the inlet. The angular deviations from the direction of the cooling fluid flow can be defined from 0-degrees to 359-degrees. The inlet arrangements can be multiple, extending along the length of the cooling surface or the engine component. Additionally, the arrangements can be disposed laterally, or a combination of longitudinally and laterally along the length of the engine component, and are not limited to the linear distributions or arrangements as shown. As such, a lateral arrangement or system of arrangements can longitudinally overlap one another along the length of the engine component.
It should be further appreciated as described herein, the arrangements of inlets are groupings of two or more film hole inlets relative to one another. The placement of the inlets should be understood as non-random. The inlets can be adjacent to or arranged relative to one another and can define hole axes relative to one another, with the axis angles being between 0-degrees and 180-degrees relative to one another. The inlets within the groups can be staggered by a hole-to-hole distance or can be staggered by a group-to-group distance, or by arrangement. The inlets can comprise arrangements having inlets with differing sizes. The film hole, inlet, outlet, or passage therethrough can be used to define the film hole size. The arrangements can further be utilized with inlet or exit hole shaping, such that inlets or outlets within arrangements comprise hole shaping relative to one another.
It should be further appreciated that two arranged inlets can have differing outlets or passages comprising the film holes. As such, similarly oriented inlets can have differently oriented outlets or film hole passages, such that the film cooling can be optimized through the placement and orientation of the inlets.
It should be further appreciated that arrangement of inlets or placement of inlets relative to one another provides for developing a fluid dynamic advantage for film cooling performance. Particular groupings or arrangements of inlets can provide for an improved cooling film provided to the hot surface of engine components, or increased efficiency or performance for film cooling. As such, a significant temperature reduction or more to a cooled component can be achieved. Time-on-wing for the engine components effectively increases. Furthermore, the arrangements can be utilized to leverage manufacturing of the engine components with the inlets, such that non-linear or compound inlets are easily manufactured. Thus, an increased flexibility for accommodating internal cooling surface shapes and features are provided.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention 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 structural elements with insubstantial differences from the literal languages of the claims.
This application is a divisional of U.S. application Ser. No. 14/950,627, filed on Nov. 24, 2015, titled “GAS TURBINE ENGINE WITH FILM HOLES”, which is hereby expressly incorporated herein by reference in its entirety.
Number | Date | Country | |
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Parent | 14950627 | Nov 2015 | US |
Child | 16039731 | US |