Patent Description:
Some components, such as hot gas path components of gas turbines, are subjected to high temperatures. At least some such components have internal cooling conduits defined therein, such as but not limited to a network of plenums and passages, that circulate a cooling fluid internally, for example, along an interior surface of the outer wall of the component. In addition, at least some such components include a coating system, such as a thermal barrier coating and bond coat, on an exterior surface of the outer wall. The coating system and cooling fluid each facilitate maintaining one or more of the exterior surface of the outer wall, other portions of the wall or substrate material of the component, the thermal barrier coating, and the bond coat below a respective threshold temperature during operation. In at least some cases, local regions of the thermal bond coat can be become spalled or otherwise damaged over an operating lifetime of the component, and an increased overall flow rate of the cooling fluid is selected to compensate for the potential loss of protection from the thermal bond coat in spalled regions. For at least some components, the spalled regions could occur at any of a number of locations on the component and at any quantity at those locations, and thus the increased overall cooling fluid flow must be provided to the entire component, rather than just to targeted regions. This may result in unnecessary overcooling of regions that do not become spalled, and thus decreased operating efficiency.

<CIT> discloses components for use in a flowpath having a wall for bounding hot combustion gases in a gas turbine engine. The wall includes opposite outer and inner surfaces and a plurality of cooling holes extending therebetween. A thermal barrier coating is bonded to the outer surface and covers blind the holes thereat.

The invention as herein claimed relates to the subject matter set forth in the claims.

Accordingly, a value modified by a term or terms such as "about," "approximately," and "substantially" is not to be limited to the precise value specified. Here and throughout the specification and claims, range limitations may be identified. Such ranges may be combined and/or interchanged, and include all the sub-ranges contained therein unless context or language indicates otherwise.

The exemplary components described herein overcome at least some of the disadvantages associated with known systems for internal cooling of a component. More specifically, the embodiments described herein include a plurality of adaptive cooling openings defined in an outer wall of a component. A coating is disposed on an exterior surface of the outer wall. Each opening extends from a first end in flow communication with at least one interior plenum of the component, outward through the exterior surface and to a second end covered underneath at least a portion of the thickness of the coating. After, for example, a spall event damages or removes the coating to a depth of the second end of the adaptive cooling openings, cooling fluid from an internal cooling fluid pathway is channeled through the adaptive cooling openings to an exterior of the component, providing additional localized cooling to mitigate, for example, the spall event.

<FIG> is a schematic view of an exemplary rotary machine <NUM> having components for which embodiments of the current disclosure may be used. In the exemplary embodiment, rotary machine <NUM> is a gas turbine that includes an intake section <NUM>, a compressor section <NUM> coupled downstream from intake section <NUM>, a combustor section <NUM> coupled downstream from compressor section <NUM>, a turbine section <NUM> coupled downstream from combustor section <NUM>, and an exhaust section <NUM> coupled downstream from turbine section <NUM>. A generally tubular casing <NUM> at least partially encloses one or more of intake section <NUM>, compressor section <NUM>, combustor section <NUM>, turbine section <NUM>, and exhaust section <NUM>. In alternative embodiments, rotary machine <NUM> is any rotary machine for which components formed with internal passages as described herein are suitable. Moreover, although embodiments of the present disclosure are described in the context of a rotary machine for purposes of illustration, it should be understood that the embodiments described herein are applicable in any context that involves a component exposed to a high temperature environment.

In the exemplary embodiment, turbine section <NUM> is coupled to compressor section <NUM> via a rotor shaft <NUM>. It should be noted that, as used herein, the term "couple" is not limited to a direct mechanical, electrical, and/or communication connection between components, but may also include an indirect mechanical, electrical, and/or communication connection between multiple components.

During operation of rotary machine <NUM>, intake section <NUM> channels air towards compressor section <NUM>. Compressor section <NUM> compresses the air to a higher pressure and temperature. More specifically, rotor shaft <NUM> imparts rotational energy to at least one circumferential row of compressor blades <NUM> coupled to rotor shaft <NUM> within compressor section <NUM>. In the exemplary embodiment, each row of compressor blades <NUM> is preceded by a circumferential row of compressor stator vanes <NUM> extending radially inward from casing <NUM> that direct the air flow into compressor blades <NUM>. The rotational energy of compressor blades <NUM> increases a pressure and temperature of the air. Compressor section <NUM> discharges the compressed air towards combustor section <NUM>.

In combustor section <NUM>, the compressed air is mixed with fuel and ignited to generate combustion gases that are channeled towards turbine section <NUM>. More specifically, combustor section <NUM> includes at least one combustor <NUM>, in which a fuel, for example, natural gas and/or fuel oil, is injected into the air flow, and the fuel-air mixture is ignited to generate high temperature combustion gases that are channeled towards turbine section <NUM>.

Turbine section <NUM> converts the thermal energy from the combustion gas stream to mechanical rotational energy. More specifically, the combustion gases impart rotational energy to at least one circumferential row of rotor blades <NUM> coupled to rotor shaft <NUM> within turbine section <NUM>. In the exemplary embodiment, each row of rotor blades <NUM> is preceded by a circumferential row of turbine stator vanes <NUM> extending radially inward from casing <NUM> that direct the combustion gases into rotor blades <NUM>. Rotor shaft <NUM> may be coupled to a load (not shown) such as, but not limited to, an electrical generator and/or a mechanical drive application. The exhausted combustion gases flow downstream from turbine section <NUM> into exhaust section <NUM>. A path of the combustion gases through rotary machine <NUM> defines a hot gas path of rotary machine <NUM>. Components of rotary machine <NUM> are designated as components <NUM>. Components <NUM> proximate the hot gas path are subjected to high temperatures during operation of rotary machine <NUM>. In alternative embodiments, component <NUM> is any component in any application that is exposed to a high temperature environment.

<FIG> is a schematic perspective view of an exemplary component <NUM>, illustrated for use with rotary machine <NUM> (shown in <FIG>). <FIG> is a schematic cross-section of component <NUM>, taken along lines <NUM>-<NUM> (shown in <FIG>). <FIG> is a schematic perspective sectional view of a portion of component <NUM>, designated as portion <NUM> in <FIG>. With reference to <FIG>, component <NUM> includes an outer wall <NUM> having a preselected thickness <NUM>. Moreover, in the exemplary embodiment, component <NUM> includes at least one internal void <NUM> defined therein. For example, a cooling fluid <NUM> is provided to internal void <NUM> during operation of rotary machine <NUM> to facilitate maintaining component <NUM> below a temperature of the hot combustion gases.

Component <NUM> is formed from a component material <NUM>. In the exemplary embodiment, component material <NUM> is a suitable nickel-based superalloy. In alternative embodiments, component material <NUM> is at least one of a cobalt-based superalloy, an iron-based alloy, and a titanium-based alloy. In other alternative embodiments, component material <NUM> is ceramic matrix composite (CMC). In still other alternative embodiments, component material <NUM> is any suitable material that enables component <NUM> to function as described herein.

In the exemplary embodiment, component <NUM> is one of rotor blades <NUM> or stator vanes <NUM>. In alternative embodiments, component <NUM> is another suitable component of rotary machine <NUM>. In still other embodiments, component <NUM> is any component in any application that is exposed to a high temperature environment.

In the exemplary embodiment, rotor blade <NUM>, or alternatively stator vane <NUM>, includes a pressure side <NUM> and an opposite suction side <NUM>. Each of pressure side <NUM> and suction side <NUM> extends from a leading edge <NUM> to an opposite trailing edge <NUM>. In addition, rotor blade <NUM>, or alternatively stator vane <NUM>, extends from a root end <NUM> to an opposite tip end <NUM>. A longitudinal axis <NUM> of component <NUM> is defined between root end <NUM> and tip end <NUM>. In alternative embodiments, rotor blade <NUM>, or alternatively stator vane <NUM>, has any suitable configuration that is capable of being formed with a preselected outer wall thickness as described herein.

Outer wall <NUM> at least partially defines an exterior surface <NUM> of component <NUM>, and an interior surface <NUM> opposite exterior surface <NUM>. In the exemplary embodiment, outer wall <NUM> extends circumferentially between leading edge <NUM> and trailing edge <NUM>, and also extends longitudinally between root end <NUM> and tip end <NUM>. In alternative embodiments, outer wall <NUM> extends to any suitable extent that enables component <NUM> to function for its intended purpose. Outer wall <NUM> is formed from component material <NUM>.

In addition, the at least one internal void <NUM> includes at least one plenum <NUM> defined interiorly to outer wall <NUM>. In the exemplary embodiment, each plenum <NUM> extends from root end <NUM> to proximate tip end <NUM>. In alternative embodiments, each plenum <NUM> extends within component <NUM> in any suitable fashion, and to any suitable extent, that enables component <NUM> to function as described herein.

For example, in the embodiment illustrated in <FIG>, component <NUM> includes an inner wall <NUM> positioned interiorly to outer wall <NUM>, and the at least one plenum <NUM> is at least partially defined by inner wall <NUM> and interior thereto. In the exemplary embodiment, the at least one plenum <NUM> includes a plurality of plenums <NUM>, each defined by inner wall <NUM> and at least one partition wall <NUM> that extends at least partially between pressure side <NUM> and suction side <NUM>. For example, in the illustrated embodiment, each partition wall <NUM> extends from outer wall <NUM> of pressure side <NUM> to outer wall <NUM> of suction side <NUM>. In alternative embodiments, at least one partition wall <NUM> extends from inner wall <NUM> of pressure side <NUM> to inner wall <NUM> of suction side <NUM>. Additionally or alternatively, at least one partition wall <NUM> extends from inner wall <NUM> to outer wall <NUM> of pressure side <NUM>, and/or from inner wall <NUM> to outer wall <NUM> of suction side <NUM>. In other alternative embodiments, the at least one internal void <NUM> includes any suitable number of plenums <NUM> defined in any suitable fashion. Inner wall <NUM> is formed from component material <NUM>.

Moreover, in some embodiments, at least a portion of inner wall <NUM> extends circumferentially and longitudinally adjacent at least a portion of outer wall <NUM> and is separated therefrom by an offset distance <NUM>, such that the at least one internal void <NUM> also includes at least one chamber <NUM> defined between inner wall <NUM> and outer wall <NUM>. In the exemplary embodiment, the at least one chamber <NUM> includes a plurality of chambers <NUM> each defined by outer wall <NUM>, inner wall <NUM>, and at least one partition wall <NUM>. In alternative embodiments, the at least one chamber <NUM> includes any suitable number of chambers <NUM> defined in any suitable fashion. In the exemplary embodiment, inner wall <NUM> has a thickness <NUM> and defines a plurality of apertures <NUM> extending therethrough, such that each chamber <NUM> is in flow communication with at least one plenum <NUM>.

In the exemplary embodiment, offset distance <NUM> is selected to facilitate effective impingement cooling of outer wall <NUM> by cooling fluid <NUM> supplied through plenums <NUM> and emitted through apertures <NUM> defined in inner wall <NUM> towards interior surface <NUM> of outer wall <NUM>. For example, but not by way of limitation, offset distance <NUM> varies circumferentially and/or longitudinally along component <NUM> to facilitate local cooling requirements along respective portions of outer wall <NUM>. In alternative embodiments, offset distance <NUM> is selected in any suitable fashion. Also in the exemplary embodiment, apertures <NUM> are arranged in a pattern <NUM> selected to facilitate effective impingement cooling of outer wall <NUM>. For example, but not by way of limitation, pattern <NUM> varies circumferentially and/or longitudinally along component <NUM> to facilitate local cooling requirements along respective portions of outer wall <NUM>. In alternative embodiments, pattern <NUM> is selected in any suitable fashion.

In some embodiments, apertures <NUM> are each sized and shaped to emit cooling fluid <NUM> therethrough in an impingement jet <NUM> towards interior surface <NUM>. For example, apertures <NUM> each have a substantially circular or ovoid cross-section. In alternative embodiments, apertures <NUM> each have any suitable shape and size that enables apertures <NUM> to be function as described herein.

In the exemplary embodiment, outer wall <NUM> substantially carries an operational load of component <NUM>, while inner wall <NUM> and/or partition walls <NUM> are formed by at least one insert baffle that carries very little loading. In alternative embodiments, inner wall <NUM> and/or partition walls <NUM> are formed integrally with outer wall <NUM> and/or carry a significant portion of the operational load of component <NUM>.

Also in the exemplary embodiment, outer wall <NUM> defines a boundary between component <NUM> and the hot gas environment, and has a thickness <NUM> selected to facilitate effective cooling of outer wall <NUM> with a reduced flow of cooling fluid <NUM> as compared to components having thicker outer walls. In alternative embodiments, outer wall thickness <NUM> is any suitable thickness that enables component <NUM> to function for its intended purpose. In certain embodiments, outer wall thickness <NUM> varies along outer wall <NUM>. In alternative embodiments, outer wall thickness <NUM> is constant along outer wall <NUM>.

In the exemplary embodiment, outer wall <NUM> includes exhaust openings <NUM> extending therethrough that, upon entry of component <NUM> into service, are not obstructed by a coating system <NUM> (described below) and that exhaust cooling fluid <NUM> from chambers <NUM> therethrough to provide a baseline film cooling of an exterior of outer wall <NUM>, in addition to the adaptive cooling described below. In alternative embodiments, outer wall <NUM> does not include exhaust openings <NUM>, and the at least one internal void <NUM> further includes at least one return channel <NUM> in flow communication with at least one chamber <NUM>, such that each return channel <NUM> provides a return fluid flow path for cooling fluid <NUM> used for impingement cooling of outer wall <NUM>. In other alternative embodiments, component <NUM> includes both exhaust openings <NUM> and return channels <NUM>. Although the at least one internal void <NUM> is illustrated as including plenums <NUM>, chambers <NUM>, and, optionally, return channels <NUM> for use in cooling component <NUM> that is one of rotor blades <NUM> or stator vanes <NUM>, it should be understood that in alternative embodiments, component <NUM> is any suitable component for any suitable application, and includes any suitable number, type, and arrangement of internal voids <NUM> that enable component <NUM> to function for its intended purpose. For example, in some embodiments, component <NUM> is not configured for impingement cooling of outer wall <NUM>.

In the exemplary embodiment, component <NUM> further includes coating system <NUM> disposed on exterior surface <NUM> of outer wall <NUM>. Coating system <NUM> is formed from at least one material selected to protect outer wall <NUM> from the high temperature environment. For example, as described in more detail with respect to <FIG>, coating system <NUM> includes a suitable bond coat layer adjacent to, and configured to adhere to, exterior surface <NUM>, and one or more suitable thermal barrier outer layers adjacent to the bond coat layer. In alternative embodiments, coating system <NUM> is formed from any suitable material or combination of materials, applied in any suitable combination of layers and thicknesses. Coating system <NUM> has a total thickness <NUM>. For clarity of illustration, coating system <NUM> is hidden in <FIG>.

For example, during operation, cooling fluid <NUM> is supplied to plenums <NUM> through root end <NUM> of component <NUM>. As the cooling fluid flows generally towards tip end <NUM>, jets <NUM> of cooling fluid <NUM> are forced through apertures <NUM> into chambers <NUM> and impinge upon interior surface <NUM> of outer wall <NUM>. In the exemplary embodiment, the used cooling fluid <NUM> then flows through exhaust openings <NUM> extending through outer wall <NUM> and coating system <NUM>. For example, cooling fluid <NUM> is exhausted into the working fluid through predefined, unobstructed exhaust openings <NUM> to facilitate a baseline film cooling of exterior surface <NUM> and coating system <NUM>, in addition to the adaptive cooling described below.

In alternative embodiments, the used cooling fluid <NUM> is channeled into return channels <NUM> and flows generally toward root end <NUM> and out of component <NUM>. In some such embodiments, the arrangement of the at least one plenum <NUM>, the at least one chamber <NUM>, and the at least one return channel <NUM> forms a portion of a cooling circuit of rotary machine <NUM>, such that used cooling fluid <NUM> is returned to a working fluid flow through rotary machine <NUM> upstream of combustor section <NUM> (shown in <FIG>). In other alternative embodiments, component <NUM> includes both return channels <NUM> and exhaust openings <NUM>, a first portion of cooling fluid <NUM> is returned to a working fluid flow through rotary machine <NUM> upstream of combustor section <NUM> (shown in <FIG>), and a second portion of cooling fluid <NUM> is exhausted into the working fluid through exhaust openings <NUM> to facilitate baseline film cooling of exterior surface <NUM> and coating system <NUM>. Although impingement flow through plenums <NUM> and chambers <NUM> and, optionally, exhaust flow through exhaust openings <NUM> or return flow through channels <NUM> is described in terms of embodiments in which component <NUM> is rotor blade <NUM> and/or stator vane <NUM>, a circuit of plenums <NUM>, chambers <NUM>, exhaust openings <NUM> and/or return channels <NUM> is suitable for any component <NUM> of rotary machine <NUM>, and additionally for any suitable component <NUM> for any other application.

Outer wall <NUM> includes a plurality of adaptive cooling openings <NUM> defined therein and extending therethrough. More specifically, adaptive cooling openings <NUM> each extend from a first end <NUM>, in flow communication with the at least one plenum <NUM>, outward through exterior surface <NUM> and to a second end <NUM>. In the exemplary embodiment, first end <NUM> is defined in and extends through interior surface <NUM> of outer wall <NUM>, and is in flow communication with the at least one plenum <NUM> via the at least one chamber <NUM>. In alternative embodiments, first end <NUM> is defined at any suitable location within outer wall <NUM> that is in flow communication with the at least one plenum <NUM>. For example, first end <NUM> is coupled in flow communication with a channel <NUM> that extends generally parallel to exterior surface <NUM> within outer wall <NUM>, as described herein with respect to <FIG>.

In some embodiments, and as illustrated in <FIG>, second end <NUM> is defined at and extends through exterior surface <NUM> of outer wall <NUM>, such that second end <NUM> is underneath an entirety of thickness <NUM> of coating system <NUM>. In other embodiments, second end <NUM> is defined in coating system <NUM> such that adaptive cooling opening <NUM> extends partially into coating system <NUM>, as will be described herein with respect to <FIG>. In either case, in the exemplary embodiment, upon entry of component <NUM> into service, second end <NUM> of each adaptive cooling opening <NUM> is covered underneath at least a portion of thickness <NUM> of coating system <NUM>, such that coating system <NUM> at least partially obstructs exhaustion of cooling fluid <NUM> through outer wall <NUM> via adaptive cooling openings <NUM>. In other words, upon entry of component <NUM> into service, adaptive cooling openings <NUM> are at least partially obstructed by coating system <NUM>. In some such embodiments, coating system <NUM> is porous such that, during operation, a portion of cooling fluid <NUM> escapes through adaptive cooling openings <NUM> even while coating system <NUM> is intact above adaptive cooling openings <NUM>, to further facilitate a baseline film cooling of exterior surface <NUM> of outer wall <NUM> and coating system <NUM>. In other such embodiments, coating system <NUM> is non-porous, such that coating system <NUM> effectively dead-ends adaptive cooling openings <NUM> while coating system <NUM> is intact above adaptive cooling openings <NUM>.

Also illustrated in <FIG> is an exemplary spalled region <NUM> from which at least a portion of coating system <NUM> has been removed while component <NUM> is in service. <FIG> is a perspective view of outer wall <NUM> of component <NUM> including the exemplary spalled region <NUM>. For example, region <NUM> is created when coating system <NUM> is spalled or otherwise degraded by the high temperature environment during operation of rotary machine <NUM> (shown in <FIG>). In some embodiments, component <NUM> is one of rotor blades <NUM> or stator vanes <NUM> of rotary machine <NUM> (shown in <FIG>), and spalled region <NUM> is formed along leading edge <NUM> of component <NUM>. In alternative embodiments, component <NUM> is any component in any application that is exposed to a high temperature environment, and/or spalled region <NUM> is formed in any location on component <NUM>.

In the embodiment illustrated in <FIG> and <FIG>, an entire thickness <NUM> of coating system <NUM> has been removed from spalled region <NUM>, directly exposing exterior surface <NUM> to a high temperature operating environment. In alternative embodiments, only a portion of thickness <NUM> is removed or damaged in spalled region <NUM>. For example, an outer layer of coating system <NUM> delaminates in spalled region <NUM>, as will be described in more detail herein with respect to <FIG>.

Damage to or removal of coating system <NUM> results in increased thermal exposure of outer wall <NUM>, and an exposed portion <NUM> of coating system <NUM>, in spalled region <NUM>. Adaptive cooling openings <NUM> enable component <NUM> to adapt to the increased need for cooling in spalled region <NUM>. More specifically, as coating system <NUM> is removed, second end <NUM> of each adaptive cooling opening <NUM> within spalled region <NUM> becomes completely unobstructed, creating a flow channel for cooling fluid <NUM> to pass from the at least one plenum <NUM> through adaptive cooling openings <NUM> to an exterior of outer wall <NUM>, thereby providing additional localized cooling (e.g., bore cooling and/or exterior film cooling) for outer wall <NUM> and exposed portions <NUM> of coating system <NUM> in spalled region <NUM>, in addition to the cooling initially provided by the internal cooling circuit within component <NUM>.

Because unobstructed flow through adaptive cooling openings <NUM> occurs only within spalled region <NUM>, the resulting adaptive cooling response is self-modulated in response to a size and location of spalled region <NUM>. In certain embodiments, although a total flow rate of cooling fluid <NUM> for component <NUM> must account for potential spalled regions <NUM> to develop, an overall flow requirement for cooling fluid <NUM> for component <NUM> nevertheless is decreased relative to a similar component designed to include permanent through-openings over larger regions of outer wall <NUM>, because the exhaust of cooling flow is adaptively limited to spalled regions <NUM> created while component <NUM> is in service. Moreover, in some embodiments, the cooling provided by adaptive cooling openings <NUM> facilitates mitigation of the spallation event, for example by maintaining an integrity of outer wall <NUM> and/or exposed portions <NUM> of coating system <NUM> in region <NUM> and preventing a size of spalled region <NUM> from growing.

In some embodiments, the system in which component <NUM> is installed, such as rotary machine <NUM> (shown in <FIG>) in the exemplary embodiment, includes additional subsystems configured to modify at least one property of cooling fluid <NUM> supplied to component <NUM> in response an occurrence of spalled regions <NUM>. For example, in some such embodiments, the system includes an auxiliary compressor <NUM> upstream of component <NUM>. Auxiliary compressor <NUM> increases a pressure, and thus a flow rate, of cooling fluid <NUM> supplied to the at least one plenum <NUM> to account for the additional flow required to feed adaptive cooling openings <NUM> in spalled region <NUM>. Additionally, in some such embodiments, the system includes a heat exchanger <NUM> upstream from auxiliary compressor <NUM> and configured to reduce a temperature of cooling fluid <NUM>. For example, heat exchanger <NUM> reducing a temperature of cooling fluid <NUM> facilitates subsequent compression of cooling fluid <NUM> by auxiliary compressor <NUM>, and/or improves a cooling effectiveness of cooling fluid <NUM> provided to component <NUM>. Alternatively, auxiliary compressor <NUM> is used without heat exchanger <NUM>.

In certain embodiments, operation of auxiliary compressor <NUM> and, if present, heat exchanger <NUM> is selectively adjusted based on a time-in-service of a plurality of components <NUM> in the system. For example, a certain level of spalling or other damage to components <NUM> is assumed based on the time-in-service, and auxiliary compressor <NUM> and heat exchanger <NUM> are adjusted to boost the flow and/or cooling effectiveness of cooling fluid <NUM> in response to the assumed level of damage. Alternatively, in some embodiments, auxiliary compressor <NUM> and heat exchanger <NUM> are actively controlled based on at least one suitable measured operating parameter of the system. For example, a detected change in value of the at least one measured operating parameter indicates that a threshold volume of cooling fluid <NUM> is flowing through spalled regions <NUM> of the plurality of components, and in response auxiliary compressor <NUM> and heat exchanger <NUM> are automatically controlled to increase a flow rate and/or cooling effectiveness of cooling fluid <NUM>. In alternative embodiments, auxiliary compressor <NUM> and heat exchanger <NUM> are operated in any suitable fashion that enables auxiliary compressor <NUM> and heat exchanger <NUM> to function as described herein. In other alternative embodiments, the system does not include auxiliary compressor <NUM> and heat exchanger <NUM>.

Although adaptive cooling openings <NUM> are illustrated in <FIG> and <FIG> as each extending from first end <NUM> to second end <NUM> in a direction generally normal to outer wall <NUM>, in certain embodiments an orientation of at least one adaptive cooling opening <NUM> is other than normal to outer wall <NUM>. More specifically, with reference to <FIG>, in certain embodiments, at least one adaptive cooling opening <NUM> is oriented at an acute angle, measured with respect to a direction <NUM> normal to outer wall <NUM>. <FIG> shows a schematic perspective view of an arrangement <NUM> of adaptive cooling openings <NUM> that are used in outer wall <NUM> according to the herein claimed invention. In <FIG>, a portion of outer wall <NUM> surrounding arrangement <NUM> of adaptive cooling openings <NUM> is rendered transparent, in dashed lines, for ease of illustration.

In the exemplary embodiment, each adaptive cooling opening <NUM> is oriented at the same acute angle <NUM> measured with respect to normal direction <NUM>, although the direction of rotation may differ, as discussed further below. In alternative embodiments, acute angle <NUM> of at least one adaptive cooling opening <NUM> differs in magnitude from acute angle <NUM> of another of adaptive cooling opening <NUM>. In certain embodiments, each acute angle <NUM> is selected to be in a range from about <NUM> degrees to about <NUM> degrees. More specifically, in the exemplary embodiment, each acute angle <NUM> is selected to be about <NUM> degrees. In alternative embodiments, each acute angle <NUM> is selected to be any suitable magnitude that enables adaptive cooling openings <NUM> to function as described herein. In some embodiments, adaptive cooling openings <NUM> oriented at acute angles <NUM> facilitates increased cooling of coating system <NUM> along exposed portions <NUM> of spalled region <NUM> (shown in <FIG>). More specifically, in some such embodiments, adaptive cooling openings <NUM> oriented at acute angles <NUM> direct cooling fluid <NUM> at least partially toward exposed portions <NUM>, rather than in normal direction <NUM>, which is generally parallel to an edge of exposed portions <NUM>. For example, cooling fluid <NUM> directed at least partially toward exposed portions <NUM> increases cooling of exposed portions <NUM>, thereby inhibiting coating system <NUM> from overheating and spalling further.

In the exemplary embodiment, arrangement <NUM> is formed by repeating groups of adaptive cooling openings <NUM> distributed across outer wall <NUM> (one group is illustrated), and each adaptive cooling opening <NUM> in the group is rotated by acute angle <NUM> in a different direction from other adaptive cooling openings <NUM> in the group. Thus, regardless of where spalled region <NUM> forms on exterior surface <NUM>, at least one of adaptive cooling openings <NUM> will be oriented at least partially toward exposed portions <NUM> of coating system <NUM>, facilitating increased cooling of exposed portions <NUM> and thereby inhibiting spalled region <NUM> from growing.

For example, in the illustrated embodiment, each of the repeating groups in arrangement <NUM> includes four adaptive cooling openings <NUM> arranged on four respective sides of a cubic section of outer wall <NUM>. Each adaptive cooling opening <NUM> in the group is rotated through acute angle <NUM> in a different direction, and the direction of rotation is advanced by <NUM> degrees with respect to an adjacent adaptive cooling opening <NUM> of the group. As a result, first end <NUM> of each adaptive cooling opening <NUM> is positioned directly underneath second end <NUM> of an adjacent adaptive cooling opening <NUM>. The illustrated arrangement <NUM> further facilitates having at least one of adaptive cooling openings <NUM> oriented at least partially toward exposed portions <NUM> of coating system <NUM>, regardless of where spalled region <NUM> forms on exterior surface <NUM>. In alternative embodiments, each group in arrangement <NUM> includes any suitable number and orientation of adaptive cooling openings <NUM> that enables arrangement <NUM> to function as described herein.

In alternative embodiments, at least some adaptive cooling openings <NUM> in each group are rotated by acute angle <NUM> in the same direction. For example, in some embodiments, outer wall <NUM> is exposed to a known, generally consistent direction of external flow <NUM> (shown in <FIG>), such as the local direction of working fluid flow through rotary machine <NUM> (shown in <FIG>). Adaptive cooling openings <NUM> are each oriented such that second end <NUM> is at least partially tilted into, i.e. at least partially facing, the direction of oncoming external flow <NUM>. Thus, upon creation of spalled region <NUM>, each adaptive cooling opening <NUM> channels cooling fluid <NUM> from second end <NUM> with a velocity component opposite to external flow direction <NUM>. Due to variation in local dynamic pressure of the approaching external flow at a leading portion <NUM> and a trailing portion <NUM> of exposed portions <NUM> of spalled region <NUM>, adaptive cooling openings <NUM> toward a central area of spalled region <NUM> will flow less cooling fluid <NUM>, while adaptive cooling openings <NUM> nearest to exposed portions <NUM> of spalled region <NUM> will flow more cooling fluid <NUM>, again inhibiting overheating and further spalling of coating system <NUM>.

In alternative embodiments, adaptive cooling openings <NUM> are oriented in any suitable fashion that enables adaptive cooling openings <NUM> to function as described herein.

<FIG> is a schematic sectional view of another exemplary embodiment of outer wall <NUM> of component <NUM>. <FIG> is a schematic sectional view of outer wall <NUM> including another exemplary spalled region <NUM>. In the illustrated embodiment, coating system <NUM> includes a bond coat layer <NUM> adjacent to, and configured to adhere to, exterior surface <NUM>, and at least one additional layer adjacent to bond coat layer <NUM>. More specifically, in the exemplary embodiment, coating system <NUM> also includes an intermediate layer <NUM> adjacent to, and configured to adhere to, bond coat layer <NUM>, and an outer, or insulating, layer <NUM> adjacent to, and configured to adhere to, intermediate layer <NUM>. For example, in the exemplary embodiment, bond coat layer <NUM> is an aluminum rich material that includes a diffusion aluminide or McrAlY, where M is iron, cobalt, or nickel, and Y is yttria or another rare earth element. In alternative embodiments, bond coat layer <NUM> is any suitable material that enables bond coat layer <NUM> to function as described herein. In the exemplary embodiment, intermediate layer <NUM> includes a yttria-stabilized zirconia. In alternative embodiments, intermediate layer <NUM> is any suitable material that enables intermediate layer <NUM> to function as described herein. In the exemplary embodiment, insulating layer <NUM> is an ultra-low thermal conductivity ceramic material that includes, for example, a zirconium or hafnium base oxide lattice structure (ZrO2 or HfO2) and an oxide stabilizer compound (sometimes referred to as an oxide "dopant") that includes one or more of ytterbium oxide (Yb2O3), yttria oxide (Y2O3), hafnium oxide (HfO2), lanthanum oxide (La2O3), tantalum oxide (Ta2O5), and zirconium oxide (ZrO2). In alternative embodiments, insulating layer <NUM> is any suitable material that enables insulating layer <NUM> to function as described herein. In alternative embodiments, coating system <NUM> includes any suitable number and type of layers.

As discussed above, adaptive cooling openings <NUM> each extend from a first end <NUM>, in flow communication with the at least one plenum <NUM>, outward through exterior surface <NUM> and to a second end <NUM>. In the embodiment illustrated in <FIG>, second end <NUM> is defined in coating system <NUM> such that adaptive cooling opening <NUM> extends partially into coating system <NUM>. Upon entry of component <NUM> into service, second end <NUM> of adaptive cooling opening <NUM> is covered underneath a portion of coating system <NUM> having a non-zero depth <NUM>.

In the exemplary embodiment, second end <NUM> is disposed within outer or insulating layer <NUM> of coating system <NUM>, such that adaptive cooling opening <NUM> extends through an entire thickness of bond coat layer <NUM> and intermediate layer <NUM>, and through a thickness of only a first, interior portion <NUM> of insulating layer <NUM>, such that second end <NUM> is covered beneath depth <NUM> of a remaining second, exterior portion <NUM> of insulating layer <NUM>. Thus, when spalled region <NUM> is created to a depth at least equal to depth <NUM> of second portion <NUM> of insulating layer <NUM>, as illustrated in <FIG>, second end <NUM> of each adaptive cooling opening <NUM> within spalled region <NUM> becomes completely unobstructed, creating a flow channel for cooling fluid <NUM> to pass from the at least one plenum <NUM> through adaptive cooling openings <NUM> to an exterior of outer wall <NUM>, thereby providing additional localized cooling (e.g., bore cooling and/or exterior film cooling) for outer wall <NUM> and exposed portions <NUM> of coating system <NUM> in spalled region <NUM>, in addition to the cooling provided by the internal cooling circuit within component <NUM>. In alternative embodiments, second end <NUM> is defined at any suitable depth <NUM> within coating system <NUM> and/or terminates at or within any suitable layer of coating system <NUM> that enables adaptive cooling openings <NUM> to function as described herein.

For example, in some embodiments, spalled region <NUM> tends to originate as a delamination of second portion <NUM> of insulating layer <NUM> from first portion <NUM> of insulating layer <NUM>, and a typical depth <NUM> of second portion <NUM> may be determined empirically for each region of outer wall <NUM>. A design position of second end <NUM> for adaptive cooling openings <NUM> in each region of outer wall <NUM> is then selected to correspond to the typical depth <NUM> for that region, such that adaptive cooling openings <NUM> become active at the most common initial delamination depth for each region of outer wall <NUM>. Thus, a depth of second end <NUM> of adaptive cooling openings <NUM> is selected to facilitate mitigation of the initial delamination spallation event, for example by maintaining an integrity of outer wall <NUM> and/or the remaining layers of coating system <NUM> in region <NUM> and/or preventing a size of spalled region <NUM> from growing. In alternative embodiments, the design position of second end <NUM> is selected in any suitable fashion that enables adaptive cooling openings <NUM> to function as described herein.

In alternative embodiments, second end <NUM> is defined at an interface between bond coat layer <NUM> and intermediate layer <NUM>, and intermediate layer <NUM> and first portion <NUM> of insulating layer <NUM> are porous materials, such that delamination or spalling of insulating layer <NUM> to depth <NUM> enables flow of cooling fluid <NUM> through second end <NUM>, porous intermediate layer <NUM>, and porous first portion <NUM> to an exterior of coating system <NUM>, as described above. In other alternative embodiments, a placement of second end <NUM> and a porosity of at least one layer of coating system <NUM> are selected in any suitable fashion to enable increased flow through adaptive cooling openings <NUM> in response to a spall or delamination event of a corresponding depth. For example, second end <NUM> is defined at the interface between bond coat layer <NUM> and intermediate layer <NUM>, and intermediate layer <NUM> is a porous material, such that delamination or spalling of an entire thickness of insulating layer <NUM> enables flow of cooling fluid <NUM> through second end <NUM> and porous intermediate layer <NUM> to an exterior of coating system <NUM>, as described above.

<FIG> is a schematic sectional view of an exemplary stage of manufacture of outer wall <NUM> as shown in <FIG>. In the exemplary embodiment, a first portion of adaptive cooling openings <NUM>, extending from first end <NUM> to exterior surface <NUM>, is initially formed in outer wall <NUM> prior to adding coating system <NUM> to outer wall <NUM>. For example, component <NUM> is initially formed with outer wall <NUM> not including adaptive cooling openings <NUM>, and the first portion of adaptive cooling openings <NUM> is subsequently formed in outer wall <NUM> by a suitable machining process. For another example, component <NUM> is initially formed with outer wall <NUM> including the first portion of adaptive cooling openings <NUM> defined therein. More specifically, outer wall <NUM> is formed by casting molten metallic component material <NUM> around a core shaped to define the first portion of adaptive cooling openings <NUM> therein, or outer wall <NUM> is formed by an additive manufacturing process in which adaptive cooling openings <NUM> are defined within thin layers of component material <NUM> deposited successively to form outer wall <NUM>.

In some embodiments, prior to or during disposing of coating system <NUM> on exterior surface <NUM>, a cap <NUM> is deployed at second end <NUM> of each adaptive cooling opening <NUM> to define adaptive cooling openings <NUM> beneath at least a portion of coating system <NUM>. In the exemplary embodiment, caps <NUM> are oblong members inserted into the first portion of adaptive cooling openings <NUM>. More specifically, each cap <NUM> extends from a first end <NUM> sized and shaped to be received in the first portion of a corresponding adaptive cooling opening <NUM>, to a second end <NUM> sized and shaped to extend outward from exterior surface <NUM> to define second end <NUM> of the corresponding adaptive cooling opening <NUM>. After caps <NUM> are positioned with second end <NUM> extending from exterior surface <NUM>, coating system <NUM> is disposed on exterior surface <NUM> around and over caps <NUM>, such as in successive layers using a suitable spray deposition process. After coating system <NUM> is formed to the selected thickness <NUM>, second end <NUM> of each cap <NUM> defines second end <NUM> of the corresponding adaptive cooling opening <NUM> at depth <NUM> within coating system <NUM>, as illustrated in <FIG>.

In another embodiment, cap <NUM> is a flat cover or blanket (not shown) that is positioned over the exposed outer end of each adaptive cooling opening <NUM> during each phase of a deposition of coating system <NUM>, until adaptive cooling openings <NUM> are defined all the way to cap <NUM> at second end <NUM>. In other alternative embodiments, caps <NUM> have any suitable structure that enables adaptive cooling openings <NUM> to be formed as described herein.

In some embodiments, after coating system <NUM> is formed, caps <NUM> are removed from outer wall <NUM> prior to entry of component <NUM> into service. For example, caps <NUM> are formed from a material that is removable from component <NUM> in a suitable leaching process prior to entry of component <NUM> into service. For another example, caps <NUM> are formed from a material that is configured to be melted and drained from component <NUM> in a suitable heating process prior to entry of component <NUM> into service. In other embodiments, caps <NUM> are not removed prior to entry of component <NUM> into service, but rather remain in place until spalled region <NUM> (shown in <FIG>) is formed over caps <NUM>. For example, caps <NUM> are formed from a material that is configured to rapidly burn away and/or fly away when caps <NUM> are exposed to the high temperature environment associated with spalled region <NUM>, thus enabling second end <NUM> of the corresponding adaptive cooling opening <NUM> to become unobstructed and create a flow channel for cooling fluid <NUM> to pass from the at least one plenum <NUM> through adaptive cooling opening <NUM> to an exterior of outer wall <NUM>, as described above.

<FIG> is a schematic sectional view of another exemplary embodiment of outer wall <NUM> including adaptive cooling openings <NUM>. A cross-sectional area <NUM> of adaptive cooling openings <NUM> is defined perpendicular to normal direction <NUM>. In certain embodiments, cross-sectional area <NUM> generally decreases between first end <NUM> and second end <NUM>. For example, in the exemplary embodiment, adaptive cooling opening <NUM> defines a generally frusto-conical shape within outer wall <NUM>, such that cross-sectional area <NUM> is generally circular and decreases between first end <NUM> and second end <NUM>. In alternative embodiments, each adaptive cooling opening <NUM> defines any suitable shape that enables adaptive cooling opening <NUM> to function as described herein.

In some such embodiments, when spalled region <NUM> (shown in <FIG>) is created over adaptive cooling opening <NUM>, successively deeper portions of coating system <NUM> and, in some cases, outer wall <NUM> oxidize, i.e., "burn through," or otherwise are removed to a depth greater than depth <NUM> of second end <NUM>. Because cross-sectional area <NUM> generally increases beyond second end <NUM> towards first end <NUM>, an increasing depth of spalled region <NUM> beyond depth <NUM> tends to correspondingly increase the exposed cross-sectional area <NUM> of adaptive cooling openings <NUM> in spalled region <NUM>, thereby increasing the escape of cooling fluid <NUM> through adaptive cooling openings <NUM> and enhancing the adaptive film cooling effect. In some such embodiments, a shape of adaptive cooling openings <NUM> is preselected to provide a varying cross-sectional area <NUM> that automatically "tunes" the amount of film cooling provided in response to a severity (e.g., width or depth) of the degradation to coating system <NUM> and/or outer wall <NUM>. For example, as material bums or flies away from exposed portions <NUM> of coating system <NUM>, cross-sectional area <NUM> opens larger and larger until enough cooling flow is being emitted from adaptive cooling openings <NUM> to stop any further degradation of coating system <NUM>.

<FIG> is a schematic sectional view of another embodiment of outer wall <NUM> of component <NUM>, including another embodiment of adaptive cooling openings <NUM>. In the embodiment of <FIG>, component <NUM> does not include inner wall <NUM> and chamber <NUM>, and outer wall <NUM> is not a relatively thin wall configured to receive impingement cooling. Outer wall <NUM> includes at least one channel <NUM> defined therein and extending generally parallel to exterior surface <NUM> at a depth <NUM> from exterior surface <NUM>. For example, the at least one channel <NUM> is a plurality of suitable microchannels <NUM> configured to channel cooling fluid <NUM> therethrough in proximity to exterior surface <NUM> to provide cooling to exterior surface <NUM>. In the exemplary embodiment, each channel <NUM> is in flow communication with the at least one plenum <NUM> via a corresponding access opening <NUM> defined within outer wall <NUM> between the at least one plenum <NUM> and a first end <NUM> of channel <NUM>. In alternative embodiments, each channel <NUM> is in flow communication with the at least one plenum <NUM> in any suitable fashion that enables channel <NUM> to function as described herein.

In certain embodiments, channel <NUM> includes turbulators <NUM> along a surface that defines channel <NUM>. Turbulators <NUM> are configured to introduce and/or increase turbulence in the flowfield of cooling fluid <NUM> within channel <NUM> to facilitate enhanced heat transfer. In the exemplary embodiment, turbulators <NUM> are implemented as a series of bumps along the surface that defines channel <NUM>. In alternative embodiments, turbulators <NUM> are implemented as one of dimples, ribs, other variations in a cross-sectional area of channel <NUM>, areas of surface roughness, and any other structure that enables turbulators <NUM> to function as described herein. In other alternative embodiments, channel <NUM> does not include turbulators <NUM>.

In the exemplary embodiment, each channel <NUM> extends to a second end (not shown) that extends through exterior surface <NUM> and coating system <NUM>, and cooling fluid <NUM> is exhausted into the working fluid through the second end of channel <NUM>. In alternative embodiments, each channel <NUM> extends to a second end (not shown) that returns cooling fluid <NUM> to another location, for example a location within rotary machine <NUM>, in a closed cooling circuit.

Each adaptive cooling opening <NUM> again extends from first end <NUM> in flow communication with the at least one plenum <NUM>, outward through exterior surface <NUM> and to a second end <NUM>. In the exemplary embodiment, first end <NUM> intersects and is in flow communication with channel <NUM>. In alternative embodiments, first end <NUM> is defined at any suitable location within outer wall <NUM> that is in flow communication with the at least one plenum <NUM> via channel <NUM> and/or access opening <NUM>.

In some embodiments, as described above, second end <NUM> is defined at and extends through exterior surface <NUM> of outer wall <NUM>. In other embodiments, second end <NUM> is defined in coating system <NUM> such that adaptive cooling opening <NUM> extends partially into coating system <NUM>, and is positioned at a depth <NUM> within coating system <NUM>. Examples of both embodiments are shown in <FIG>. In either case, upon entry of component <NUM> into service, second end <NUM> of each adaptive cooling opening <NUM> is covered underneath at least a portion of coating system <NUM>, such that cooling fluid <NUM> cannot be exhausted through outer wall <NUM> via adaptive cooling openings <NUM>. In other words, upon entry of component <NUM> into service, adaptive cooling openings <NUM> again are dead-ended by coating system <NUM>. Thus, when spalled region <NUM> is created to a depth at least equal to depth <NUM> of second portion <NUM> of insulating layer <NUM>, as illustrated in <FIG>, second end <NUM> of each adaptive cooling opening <NUM> within spalled region <NUM> becomes unobstructed, creating a flow channel for cooling fluid <NUM> to pass from the at least one plenum <NUM> through adaptive cooling openings <NUM> to an exterior of outer wall <NUM>, as described above.

Although adaptive cooling openings <NUM> are illustrated in <FIG> as each extending from first end <NUM> to second end <NUM> in direction <NUM> generally normal to outer wall <NUM>, in certain embodiments an orientation of at least one adaptive cooling opening <NUM> is again other than normal to outer wall <NUM>. More specifically, in certain embodiments, at least one adaptive cooling opening <NUM> is again oriented at an acute angle <NUM>, relative to direction <NUM>, as described above with respect to <FIG>, for example. Moreover, in some such embodiments, groups of adaptive cooling openings <NUM> are oriented in arrangement <NUM> or another suitable arrangement, also as described above with respect to <FIG>, for example to facilitate directing cooling fluid <NUM> toward exposed portions <NUM> of spalled region <NUM> and/or to facilitate channeling cooling fluid <NUM> from second end <NUM> with a velocity component opposite to external flow direction <NUM> (shown in <FIG>).

The above-described embodiments enable improved mitigation of spalling or other degradation of exterior surfaces of internally cooled components, as compared to at least some known cooling systems. Specifically, the embodiments described herein include a component that includes a coating system disposed on the exterior surface, and a plurality of adaptive cooling openings defined in the outer wall. Each of the adaptive cooling openings extends from a first end in flow communication with at least one plenum interior to the component, outward through the exterior surface and to a second end covered underneath at least a portion of the thickness of the coating system, such that flow through the adaptive cooling openings is obstructed by the coating system when the component enters into service. Once in service, local damage to the coating system, for example by a spall event, uncovers the second end of the adaptive cooling openings, and cooling fluid from an internal cooling fluid pathway is channeled through the adaptive cooling openings to an exterior of the component, providing localized film or bore cooling to mitigate, for example, the spall event. Also specifically, in some embodiments, the adaptive cooling openings are oriented within the outer wall to facilitate inhibiting the spalled region from growing, for example by ensuring that at least some adaptive cooling openings are angled towards the edge of the spalled region, wherever it may occur.

An exemplary technical effect of the methods, systems, and apparatus described herein includes at least one of: (a) mitigating an effect of spalling or other degradation of a thermal barrier coating on the exterior surface and/or on the remaining coating of an internally cooled component; (b) selecting a depth of the ends of the adaptive cooling openings underneath the initial thickness of the coating system based on empirical observation of the most common local depth of spall and/or other coating system delamination events; and (c) automatically "modulating" an amount of additional local cooling based on the size and depth of the spall region.

Exemplary embodiments of adaptively cooled components are described above in detail. The components, and methods and systems using such components, are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the exemplary embodiments can be implemented and utilized in connection with many other applications that are currently configured to use components in high temperature environments.

Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.

Claim 1:
A component (<NUM>) for a gas turbine engine, comprising:
an outer wall (<NUM>) comprising an exterior surface (<NUM>);
at least one plenum (<NUM>) defined interiorly to the outer wall (<NUM>) and configured to receive a cooling fluid (<NUM>) therein;
a coating system (<NUM>) disposed on the exterior surface (<NUM>), the coating system (<NUM>) having a thickness (<NUM>); and
a plurality of adaptive cooling openings (<NUM>) defined in the outer wall (<NUM>), wherein each of the adaptive cooling openings (<NUM>) extends from a first end (<NUM>) in flow communication with the at least one plenum (<NUM>), outward through the exterior surface (<NUM>) and to a second end (<NUM>) covered underneath at least a portion of the thickness (<NUM>) of the coating system (<NUM>),
wherein at least one of the adaptive cooling openings (<NUM>) is oriented at an acute angle relative to a direction normal to the outer wall (<NUM>),
characterized in further comprising groups of the adaptive cooling openings (<NUM>) in an arrangement, wherein each of the adaptive cooling openings (<NUM>) in each of the groups is rotated by the acute angle in a different direction from others of the adaptive cooling openings (<NUM>) in the group.