Patent Description:
Gas turbine systems are one example of turbomachines widely utilized in fields such as power generation. A conventional gas turbine system generally includes a compressor section, a combustor section, and a turbine section. During operation of a gas turbine system, various components in the gas turbine system, such as nozzle vanes, and turbine blades, and shroud segments are subjected to high temperature gas flows and associated thermal-mechanical forces, which can cause the components to fail.

<CIT> and <CIT> each disclose a nozzle segment comprising a vane having the features of the preamble of independent claim1.

<CIT> discloses a nozzle vane comprising an internal cavity configured to receive a flow of cooling fluid, a wall surrounding the internal cavity, first and second impingement devices arranged inside the internal cavity and a number of spacers which are integrally formed with the wall and are embodied as ribs or protrusions configured to hold the first and second impingement devices at a predetermined distance to the inner surface of the wall.

<CIT> discloses a nozzle vane of a turbine engine, comprising a variable thickness wall defining a number of internal cavities configured to receive a cooling fluid flow, wherein the thickness of the variable thickness wall varies in the radial direction and around the cross-section of the vane such that the variable thickness wall is thicker in hot areas of the vane wall which have higher local thermal stresses when exposed to a hot gas within the turbine engine.

A first aspect of the invention is directed to a vane of a turbine system. The vane includes: an internal cavity configured to receive a flow of cooling fluid; a variable thickness wall adjacent the internal cavity; and an impingement plate separating the variable thickness wall from the internal cavity, the impingement plate including a plurality of apertures for directing the cooling fluid into an impingement cavity and against the variable thickness wall, wherein the impingement plate is configured to follow a contour of the variable thickness wall. The impingement plate has a variable thickness, wherein the thickness of each section of the impingement plate is inversely proportional to a thickness of an adjacent section of the variable thickness wall such that the impingement plate is thicker adjacent a thinner section of the variable thickness wall and thinner adjacent a thicker section of the variable thickness wall.

Another embodiment provides a nozzle segment for a gas turbine system. The nozzle segment includes an integrated nozzle and diaphragm, the nozzle including at least one vane as described before.

The illustrative aspects of the present disclosure solve the problems herein described and/or other problems not discussed.

These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure.

Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.

As an initial matter, in order to clearly describe the current disclosure, it will become necessary to select certain terminology when referring to and describing relevant machine components within the scope of this disclosure. When doing this, if possible, common industry terminology will be used and employed in a manner consistent with its accepted meaning. Unless otherwise stated, such terminology should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. Those of ordinary skill in the art will appreciate that often a particular component may be referred to using several different or overlapping terms. What may be described herein as being a single part may include and be referenced in another context as consisting of multiple components. Alternatively, what may be described herein as including multiple components may be referred to elsewhere as a single part.

In addition, several descriptive terms may be used regularly herein, and it should prove helpful to define these terms at the onset of this section. These terms and their definitions, unless stated otherwise, are as follows. As used herein, "downstream" and "upstream" are terms that indicate a direction relative to the flow of a fluid, such as the working fluid through the turbine or, for example, the flow of air through the combustor or coolant through one of the turbine's component systems. The term "downstream" corresponds to the direction of flow of the fluid, and the term "upstream" refers to the direction opposite to the flow. The terms "forward" and "aft," without any further specificity, refer to directions, with "forward" referring to the front or compressor end of the engine, and "aft" referring to the rearward or turbine end of the engine. Additionally, the terms "leading" and "trailing" may be used and/or understood as being similar in description as the terms "forward" and "aft," respectively. It is often required to describe parts that are at differing radial, axial and/or circumferential positions. The "A" axis represents an axial orientation. As used herein, the terms "axial" and/or "axially" refer to the relative position/direction of objects along axis A, which is substantially parallel with the axis of rotation of the gas turbine system (in particular, the rotor section). As further used herein, the terms "radial" and/or "radially" refer to the relative position/direction of objects along a direction "R" (see, <FIG>), which is substantially perpendicular with axis A and intersects axis A at only one location. Finally, the term "circumferential" refers to movement or position around axis A (e.g., direction "C").

In various embodiments, components described as being "fluidly coupled" to or "in fluid communication" with one another can be joined along one or more interfaces. In some embodiments, these interfaces can include junctions between distinct components, and in other cases, these interfaces can include a solidly and/or integrally formed interconnection. That is, in some cases, components that are "coupled" to one another can be simultaneously formed to define a single continuous member. However, in other embodiments, these coupled components can be formed as separate members and be subsequently joined through known processes (e.g., fastening, ultrasonic welding, bonding).

When an element or layer is referred to as being "on", "engaged to", "connected to" or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to", "directly connected to" or "directly coupled to" another element, there may be no intervening elements or layers present.

<FIG> depicts a schematic diagram of a gas turbine system <NUM> according to various embodiments. As shown, the gas turbine system <NUM> includes a compressor section <NUM> for compressing an incoming flow of air <NUM> and for delivering a flow of compressed air <NUM> to a combustor section <NUM>. The combustor section <NUM> mixes the flow of compressed air <NUM> with a pressurized supply of fuel <NUM> and ignites the mixture to create a flow of combustion gases <NUM>. Although only a single combustor section <NUM> is shown, the gas turbine system <NUM> may include any number of combustor sections <NUM>. The flow of combustion gases <NUM> is in turn delivered to a turbine section <NUM>. The flow of combustion gases <NUM> drives the turbine section <NUM> to produce mechanical work. The mechanical work produced in the turbine section <NUM> may drive the compressor section <NUM> via a shaft <NUM> and may be used to drive an external load <NUM>, such as an electrical generator and/or the like.

<FIG> is a cross-sectional side view of a portion of a turbine section <NUM> of a gas turbine system <NUM> that may incorporate various embodiments disclosed herein. As shown in <FIG>, the turbine section <NUM> may include multiple turbine stages. For example, the turbine section <NUM> may include a first turbine stage 30A, a second turbine stage 30B, and a third turbine stage 30C. However, the turbine section <NUM> may include more or less turbine stages as is necessary or desired.

Each turbine stage 30A-30C may include, in serial flow order, a corresponding row of turbine nozzles (hereafter "nozzles") 32A, 32B, and 32C and a corresponding row of turbine blades (hereafter "blades) 34A, 34B, and 34C axially spaced apart along the shaft <NUM> (<FIG>). Each of the nozzles 32A-32C remains stationary relative to the blades 34A-34C during operation of the gas turbine system <NUM>. Each of the rows of nozzles 32B, 32C is respectively coupled to or formed integrally with a corresponding diaphragm 42B, 42C. Turbine shroud 44A, turbine shroud 44B, and turbine shroud 44C circumferentially enclose the corresponding row of blades 34A-34C. A casing or shell <NUM> circumferentially surrounds each stage 30A-30C of the nozzles 32A-32C and blades 34A-34C.

The nozzles 32A-32C and blades 34A-34C extract kinetic and/or thermal energy from the combustion gases <NUM>. This energy extraction drives the shaft <NUM>. The combustion gases <NUM> then exit the turbine section <NUM> and the gas turbine system <NUM>. As will be discussed in greater detail below, a portion of the compressed air <NUM> may be used as a cooling fluid for cooling the various components of the turbine section <NUM> including, inter alia, the nozzles 32A-32C and blades 34A-34C.

<FIG> is an isometric view of a nozzle segment <NUM> including an integrated nozzle <NUM> and diaphragm <NUM> according to embodiments. The nozzle <NUM> and diaphragm <NUM> may be formed as a single unit using, for example, an additive manufacturing process. As shown in <FIG>, the nozzle <NUM> may include an inner side wall <NUM> (which also forms an upper wall of the diaphragm <NUM>) and an outer side wall <NUM> radially spaced apart from the inner side wall <NUM>. The nozzle <NUM> may include a pair of vanes <NUM> that extend in span from the inner side wall <NUM> to the outer side wall <NUM>. This nozzle configuration is commonly referred to in the industry as a doublet. However, the nozzle <NUM> may have only one vane <NUM> (i.e., a singlet) or three (i.e., a triplet) or more vanes <NUM>.

As illustrated in <FIG>, the inner and the outer side walls <NUM>, <NUM> of the nozzle <NUM> include various surfaces. More specifically, the inner side wall <NUM> includes a radially outer surface <NUM> and a radially inner surface <NUM> positioned radially inwardly from the radially outer surface <NUM>. Similarly, the outer side wall <NUM> includes a radially inner surface <NUM> and a radially outer surface <NUM> oriented radially outwardly from the radially inner surface <NUM>. The radially inner surface <NUM> of the outer side wall <NUM> and the radially outer surface <NUM> of the inner side wall <NUM> respectively define inner and outer radial flow boundaries for the combustion gases <NUM> flowing through the turbine section <NUM> (<FIG>).

As mentioned above, two vanes 52A, 52B (generally referred to herein as vanes <NUM>) extend from the inner side wall <NUM> to the outer side wall <NUM> of the nozzle <NUM>. As illustrated in <FIG>, the body of each vane <NUM> includes a leading edge <NUM>, a trailing edge <NUM>, a pressure side wall <NUM>, and an opposing suction side wall <NUM> extending from the leading edge <NUM> to the trailing edge <NUM>.

A cooling fluid, such as pressurized cooling air <NUM> bled off from the compressor section <NUM> of the turbine system <NUM> (<FIG>), may be routed into one or more internal cavities <NUM> formed within each vane <NUM>. The cooling air <NUM> may be used to cool (e.g., through impingement cooling, convection cooling, film cooling, etc.) various internal and external portions of the vane <NUM>.

Various portions of a vane <NUM> of a nozzle <NUM>, including the leading edge <NUM> and what is known in the art as the high-c area, may be subject to high temperatures and high mechanical forces during operation of the turbine system <NUM> (<FIG>), which can lead to a reduction in the operational lifetime of the nozzle <NUM>. According to embodiments, the operational lifetime of the nozzle <NUM> may be increased, for example, by preferentially varying the thicknesses of various portions of the vanes <NUM> (e.g., thicker in regions subject to higher forces, thinner in regions subject to lower forces) and by providing a contour-following impingement plate <NUM> (<FIG>) within the vanes <NUM>.

<FIG> depicts a cross-sectional view of the vanes 52A, 52B of the nozzle <NUM> taken along line <NUM> - <NUM> in <FIG>. As shown, each vane 52A, 52B includes at least one internal cavity <NUM> configured to receive a flow of cooling air <NUM>. Cooling air <NUM> is shown as flowing radially downward (i.e., into the page) into the cavities <NUM>, although other flow directions may be used. The internal cavities <NUM> of the vanes 52A, 52B may have different configurations as shown (e.g., the wall thicknesses of the vanes 52A, 52B may be different) or may have a similar configuration. In the non-limiting example shown in <FIG>, the flow of cooling air <NUM> is directed radially downward into the internal cavities <NUM> toward the diaphragm <NUM> (<FIG>).

The impingement plate <NUM> may extend continuously about the internal cavity <NUM> as shown, or may include a plurality of separate impingement plate sections. In general, the impingement plate <NUM> directs cooling air <NUM> from the internal cavity <NUM> of each vane <NUM>, through a plurality of apertures <NUM> (<FIG>) formed through the impingement plate <NUM>, into an impingement cavity <NUM>. After entering the cavity <NUM>, the cooling air <NUM> impinges against various interior wall(s) of the vane <NUM> (e.g., pressure side wall <NUM> and suction side wall <NUM> of the vane <NUM>), providing impingement cooling. The cooling air <NUM> may be directed from the cavity <NUM> to other internal/external portions of the vane <NUM> to provide additional cooling to the vane <NUM>.

The thicknesses of one or more portions of the vane <NUM> (e.g., pressure side wall <NUM>, suction side wall <NUM>, leading edge wall <NUM>, trailing edge wall <NUM>, etc.) may be preferentially varied in accordance with expected (or estimated) operational forces. The operational forces on the vane <NUM> may be determined, for example, via computer modeling, physical testing, or other suitable analysis techniques. This may include, for example, modeling and analyzing the operational forces using an engineering simulation tool, modifying one or more of the thicknesses, and rerunning the analysis. In <FIG>, for example, the pressure side wall <NUM> of the vane <NUM> has been formed with a substantially uniform thickness, since operational forces are expected to be relatively uniform along the length of the pressure side wall <NUM>. However, a radially outward portion <NUM> of the suction side wall <NUM> (e.g., in the hi-c region) is formed with a thickness greater than that of a radially inward portion <NUM> of the suction side wall <NUM>, since operational forces are expected to be greater at the radially outward portion <NUM> of the suction side wall <NUM>. In general, the thicknesses of one or more portions of the vane <NUM> is proportional to expected operational forces. For example, according to embodiments, the thickness of the suction side wall <NUM> in the hi-c area (e.g., see <FIG>) may be on the order of about <NUM> to about <NUM> times the nominal wall thickness (e.g., the thickness of the pressure-side wall <NUM>) of the vane <NUM>. In general, depending on expected operational forces, the wall thickness of portions of the walls of the vane <NUM> may be in the range of <NUM> to <NUM> X the nominal wall thickness of the vane <NUM>.

According to embodiments, the impingement plate <NUM> is configured to follow the contours of the interior walls of the vane <NUM>. For example, as shown in <FIG>, the impingement plate <NUM> is configured to follow the contours of the inner side walls <NUM>, <NUM> of the pressure and suction side walls <NUM>, <NUM> of the vane <NUM>. Advantageously, by following the contours of the interior walls of the vane <NUM>, the distance D between the impingement plate <NUM> and the interior walls of the vane <NUM> (and the impingement cooling provided via the impingement plate <NUM>) can be more accurately controlled (e.g., as compared to impingement plate inserts). The distance D may be substantially constant throughout the vane <NUM> or may be variable (e.g., to selectively adjust the resultant impingement cooling).

A set of support beams <NUM> may be provided to connect and separate the impingement plate <NUM> to/from the inner side walls <NUM>, <NUM> of the pressure and suction side walls <NUM>, <NUM>. The support beams <NUM> provide several functions. For example, the support beams <NUM> connect the impingement plate and provide structural support/stiffness for the pressure and suction side walls <NUM>, <NUM>, allowing the pressure and suction side walls <NUM>, <NUM> of the vane <NUM> to be made thinner. Further, the support beams <NUM> maintain and control the distance D between the impingement plate <NUM> and the inner side walls <NUM>, <NUM> of the pressure and suction side walls <NUM>, <NUM>. With thinner walls, the cooling air <NUM> can more effectively cool the hot side of a vane <NUM>. For example, instead of having the vane <NUM> be <NUM> (<NUM>") thick, it can be made <NUM> (<NUM>") thick and the impingement plate <NUM> can be made <NUM> (<NUM>") thick. The resulting structure has a similar stiffness, but a better cooling effectiveness. Thus, the amount of cooling air <NUM> needed to cool the structure is reduced and the life of the structure may be extended. This also provides the ability to tune specific locations to be thinner or thicker than the average to address stress and oxidation concerns.

According to the invention, the thickness TIP of the (<NUM>, <NUM>, <NUM>, <NUM>) varies within the vane <NUM>. In particular, the thickness TIP of the impingement plate <NUM> is inversely proportional to a thickness Tw (<FIG>) of an adjacent interior wall section. As such, the impingement plate <NUM> is thicker adjacent a thinner interior wall section (e.g., to provide additional structural support) and thinner adjacent a thicker interior wall section.

<FIG> depicts a cross-sectional view of the leading edge <NUM> of the vane <NUM> taken along line <NUM> - <NUM> in <FIG>. During operation, a radially outward section <NUM> of the leading edge wall <NUM> of the vane <NUM> may experience higher forces than a radially inward section <NUM> of the leading edge wall <NUM>. To this extent, according to embodiments, the thickness of the leading edge wall <NUM> may be preferentially varied such that higher forces regions (e.g., the radially outward section <NUM>) are thicker than lower force regions (the radially inward section <NUM>).

In addition to any impingement cooling provided to the inner side wall <NUM> of the leading edge wall <NUM> of the vane <NUM> via the impingement plate <NUM>, further cooling may be required at the thickened section <NUM> of the leading edge wall <NUM>. Such cooling may be provided, for example, by forming a channel <NUM> through the thickened section <NUM> of the leading edge wall <NUM>, extending from the internal cavity <NUM> to the cavity <NUM>.

The channel <NUM> is fluidly coupled to the cavity <NUM>, which is further fluidly coupled to a channel <NUM> formed through the inner side wall <NUM> of the nozzle <NUM>. After passing from the cavity <NUM> through the channel <NUM> and absorbing heat from the thickened section <NUM> of the leading edge wall <NUM>, cooling air <NUM> passes out of the cavity <NUM> into an internal cavity <NUM> of the diaphragm <NUM> through the channel <NUM>. The cooling air <NUM> entering the cavity <NUM> through the channel <NUM> may pressurize the cavity <NUM> (e.g., to prevent hot gasses from entering the cavity <NUM>) and/or may provide cooling to the inner side wall <NUM> of the nozzle <NUM>. Yet another channel <NUM> may be provided to fluidly couple the cavity <NUM> to the wheel space <NUM> of the turbine section <NUM> (<FIG>). The channel <NUM> may extend from the cavity <NUM> to the wheel space <NUM>, for example, through the inner side wall <NUM> of the nozzle <NUM> and a side wall <NUM> of the diaphragm <NUM>. The cooling air <NUM> flowing through the channel <NUM> may provide cooling to the inner side wall <NUM> of the nozzle <NUM> and the side wall <NUM> of the diaphragm <NUM>, and/or may be used to pressurize the wheel space <NUM> to keep hot gasses from entering the wheel space <NUM>.

<FIG> depicts a cross-sectional view of the nozzle segment <NUM> taken from the leading edge <NUM> to the trailing edge <NUM> of a vane <NUM> according to embodiments. To this extent, <FIG> includes the features at the leading edge <NUM> of the vane <NUM> previously described above with regard to <FIG>.

As shown in <FIG>, the impingement plate <NUM> follows the contours of the inner side wall <NUM> of the trailing edge wall <NUM> of the trailing edge <NUM> of the vane <NUM>. Cooling air <NUM> passes through the plurality of apertures <NUM> formed in the impingement plate <NUM> and into the cavity <NUM>, where the cooling air <NUM> impinges against the inner side wall <NUM> of the trailing edge wall <NUM>, providing impingement cooling.

The cavity <NUM> may be fluidly coupled to at least one of a trailing edge cooling circuit <NUM> and a channel <NUM> formed through the inner side wall <NUM> of the nozzle <NUM>. After impinging on the inner side wall <NUM> of the trailing edge wall <NUM>, cooling air <NUM> may pass out of the cavity <NUM> into the internal cavity <NUM> of the diaphragm <NUM> through the channel <NUM> and/or may pass out of the cavity <NUM> to the trailing edge cooling circuit <NUM>. The cooling air <NUM> entering the cavity <NUM> through the channel <NUM> combines with the cooling air <NUM> entering the cavity <NUM> through the channel <NUM> to pressurize the cavity <NUM> (e.g., to prevent hot gasses from entering the cavity <NUM>) and/or provide cooling to the inner side wall <NUM> of the nozzle <NUM>.

An additional channel <NUM> may be provided to fluidly couple the cavity <NUM> to the wheel space <NUM> of the turbine section <NUM> (<FIG>). The channel <NUM> may extend from the cavity <NUM> to the wheel space <NUM>, for example, through the inner side wall <NUM> of the nozzle <NUM> and a side wall <NUM> of the diaphragm <NUM>. The cooling air <NUM> flowing through the channel <NUM> may provide cooling to the inner side wall <NUM> of the nozzle <NUM> and the side wall <NUM> of the diaphragm <NUM>, and/or be used to pressurize the wheel space <NUM> to keep hot gasses from entering the wheel space <NUM>.

The support beams <NUM> formed between the impingement plate <NUM> and the inner side walls <NUM>, <NUM> of the leading and trailing edge walls <NUM>, <NUM> provide structural support/stiffness for the leading and trailing edge walls <NUM>, <NUM>, which allows the leading and trailing edge walls <NUM>, <NUM> of the vane <NUM> to be made thinner. Further, the support beams <NUM> maintain and control the separation between the impingement plate <NUM> and the inner side walls <NUM>, <NUM> of the leading and trailing edge walls <NUM>, <NUM>.

Although described above with regard to turbine nozzle segment <NUM>, some/all of the embodiments described herein may also be applied to other components of a gas turbine system <NUM>. For example, some/all of the embodiments described herein may be applied to a turbine blade <NUM>, shroud <NUM>, or other component(s) of the turbine system <NUM>.

Various components and features of the nozzle segment <NUM> of the present disclosure may be formed using an additive manufacturing process. Advantageously, additive manufacturing enables the design and production of more customizable features (e.g., vanes <NUM> with optimized wall thicknesses, contour-following impingement plate <NUM>, etc.) as well as more intricate features (e.g., support beams <NUM>), to provide better aerodynamic and high temperature efficiencies. Further, using additive manufacturing, the size (e.g., diameter, length) of various channels (e.g., channels <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) within the vanes <NUM> and diaphragm <NUM> of the nozzle segment <NUM> can be customized/optimized to reduce flow losses and to increase cooling efficiencies. In addition, features such as the contour-following impingement plate <NUM> and the support beams <NUM> may be formed integrally with the walls of the vane <NUM>.

As detailed above, the operational lifetime of the nozzle <NUM> may be increased, for example, by preferentially varying the thicknesses of various portions (e.g., walls, impingement plate, etc.) of the vanes <NUM>. A flow diagram of a process for optimizing wall thicknesses in a vane <NUM> is provided in <FIG>.

At process A1, an analysis is performed to determine the expected operational forces on various portions (e.g., pressure side wall <NUM>, suction side wall <NUM>, leading edge wall <NUM>, trailing edge wall <NUM>, etc.) of a vane <NUM>. The analysis may be performed, for example, on a design of the vane <NUM>, a physical model of the vane <NUM>, or on the vane <NUM> itself. At process A2, the design of the vane <NUM> is modified by preferentially varying the thicknesses of one or more walls of the vane <NUM> based on the expected operational forces. Processes A1 and A2 may be repeated as necessary on the updated design of the vane <NUM> (YES at process A3) to further optimize the wall thicknesses of the vane <NUM>.

As used herein, additive manufacturing may include any process of producing an object through the successive layering of material rather than the removal of material, which is the case with conventional processes. Additive manufacturing can create complex geometries without the use of any sort of tools, molds or fixtures, and with little or no waste material. Instead of machining components from solid billets of plastic or metal, much of which is cut away and discarded, the only material used in additive manufacturing is what is required to shape the part. Additive manufacturing processes may include but are not limited to: 3D printing, rapid prototyping (RP), direct digital manufacturing (DDM), binder jetting, selective laser melting (SLM) and direct metal laser melting (DMLM). In the current setting, DMLM or SLM have been found advantageous.

To illustrate an example of an additive manufacturing process, <FIG> shows a schematic/block view of an illustrative computerized additive manufacturing system <NUM> for generating an object <NUM>. In this example, the system <NUM> is arranged for DMLM. It is understood that the general teachings of the disclosure are equally applicable to other forms of additive manufacturing. The object <NUM> is illustrated as a nozzle segment <NUM> (<FIG>). The AM system <NUM> generally includes a computerized additive manufacturing (AM) control system <NUM> and an AM printer <NUM>. The AM system <NUM>, as will be described, executes code <NUM> that includes a set of computer-executable instructions defining the object <NUM> to physically generate the object <NUM> using the AM printer <NUM>. Each AM process may use different raw materials in the form of, for example, fine-grain powder, liquid (e.g., polymers), sheet, etc., a stock of which may be held in a chamber <NUM> of the AM printer <NUM>. In the instant case, the nozzle segment <NUM> may be made of a metal or metal compound capable of withstanding the environment of a gas turbine system <NUM> (<FIG>). As illustrated, an applicator <NUM> may create a thin layer of raw material <NUM> spread out as the blank canvas on a build plate <NUM> of AM printer <NUM> from which each successive slice of the final object will be created. In other cases, the applicator <NUM> may directly apply or print the next layer onto a previous layer as defined by code <NUM>, e.g., where a metal binder jetting process is used. In the example shown, a laser or electron beam <NUM> fuses particles for each slice, as defined by code <NUM>, but this may not be necessary where a quick setting liquid plastic/polymer is employed. Various parts of the AM printer <NUM> may move to accommodate the addition of each new layer, e.g., a build platform <NUM> may lower and/or chamber <NUM> and/or applicator <NUM> may rise after each layer.

The AM control system <NUM> is shown implemented on a computer <NUM> as computer program code. To this extent, the computer <NUM> is shown including a memory <NUM>, a processor <NUM>, an input/output (I/O) interface <NUM>, and a bus <NUM>. Further, the computer <NUM> is shown in communication with an external I/O device/resource <NUM> and a storage system <NUM>. In general, the processor <NUM> executes computer program code, such as the AM control system <NUM>, that is stored in memory <NUM> and/or storage system <NUM> under instructions from code <NUM> representative of the object <NUM>, described herein. While executing computer program code, the processor <NUM> can read and/or write data to/from memory <NUM>, storage system <NUM>, I/O device <NUM>, and/or AM printer <NUM>. The bus <NUM> provides a communication link between each of the components in the computer <NUM>, and the I/O device <NUM> can comprise any device that enables a user to interact with computer <NUM> (e.g., keyboard, pointing device, display, etc.). The computer <NUM> is only representative of various possible combinations of hardware and software. For example, the processor <NUM> may comprise a single processing unit, or be distributed across one or more processing units in one or more locations, e.g., on a client and server. Similarly, the memory <NUM> and/or storage system <NUM> may reside at one or more physical locations. The memory <NUM> and/or storage system <NUM> can comprise any combination of various types of non-transitory computer readable storage medium including magnetic media, optical media, random access memory (RAM), read only memory (ROM), etc. The computer <NUM> can comprise any type of computing device such as a network server, a desktop computer, a laptop, a handheld device, a mobile phone, a pager, a personal data assistant, etc..

Additive manufacturing processes begin with a non-transitory computer readable storage medium (e.g., memory <NUM>, storage system <NUM>, etc.) storing code <NUM> representative of the object <NUM>. For example, the code <NUM> may include a precisely defined 3D model of the object <NUM> and can be generated from any of a large variety of well-known computer aided design (CAD) software systems such as AutoCAD®, TurboCAD®, DesignCAD 3D Max, etc. In this regard, the code <NUM> can take any now known or later developed file format. For example, the code <NUM> may be in the Standard Tessellation Language (STL) which was created for stereolithography CAD programs of 3D Systems, or an additive manufacturing file (AMF), which is an American Society of Mechanical Engineers (ASME) standard that is an extensible markup-language (XML) based format designed to allow any CAD software to describe the shape and composition of any three-dimensional object to be fabricated on any AM printer. The code <NUM> may be translated between different formats, converted into a set of data signals and transmitted, received as a set of data signals and converted to code, stored, etc., as necessary. The code <NUM> may be an input to system <NUM> and may come from a part designer, an intellectual property (IP) provider, a design company, the operator or owner of system <NUM>, or from other sources. In any event, the AM control system <NUM> executes the code <NUM>, dividing the object <NUM> into a series of thin slices that it assembles using the AM printer <NUM> in successive layers of liquid, powder, sheet or other material. In the DMLM example, each layer is melted to the exact geometry defined by the code <NUM> and fused to the preceding layer. Subsequently, the object <NUM> may be exposed to any variety of finishing processes, e.g., those described herein for re-contouring or other minor machining, sealing, polishing, etc..

Claim 1:
A vane (<NUM>) for a gas turbine system, comprising:
an internal cavity (<NUM>) configured to receive a flow of cooling fluid;
a variable thickness wall (<NUM>, <NUM>, <NUM>, <NUM>) adjacent the internal cavity (<NUM>); and
an impingement plate (<NUM>) separating the variable thickness wall (<NUM>, <NUM>, <NUM>, <NUM>) from the internal cavity (<NUM>), the impingement plate (<NUM>) including a plurality of apertures (<NUM>) for directing the cooling fluid into an impingement cavity (<NUM>) and against the variable thickness wall (<NUM>, <NUM>, <NUM>, <NUM>), wherein the impingement plate (<NUM>) is configured to follow a contour of the variable thickness wall (<NUM>, <NUM>, <NUM>, <NUM>);
characterized in that the impingement plate (<NUM>) has a variable thickness (TIP), wherein the thickness (TIP) of each section of the impingement plate (<NUM>) is inversely proportional to a thickness (Tw) of an adjacent section of the variable thickness wall (<NUM>, <NUM>, <NUM>, <NUM>) such that the impingement plate (<NUM>) is thicker adjacent a thinner section of the variable thickness wall (<NUM>, <NUM>, <NUM>, <NUM>) and thinner adjacent a thicker section of the variable thickness wall (<NUM>, <NUM>, <NUM>, <NUM>).