Patent Description:
Turbomachines are utilized in a variety of industries and applications for energy transfer purposes. For example, a gas turbine engine generally includes a compressor section, a combustion section, a turbine section, and an exhaust section. The compressor section progressively increases the pressure of a working fluid entering the gas turbine engine and supplies this compressed working fluid to the combustion section. The compressed working fluid and a fuel (e.g., natural gas) mix within the combustion section and burn in a combustion chamber to generate high pressure and high temperature combustion gases. The combustion gases flow from the combustion section into the turbine section where they expand to produce work. For example, expansion of the combustion gases in the turbine section may rotate a rotor shaft connected, e.g., to a generator to produce electricity. The combustion gases then exit the gas turbine via the exhaust section.

The combustion section of a gas turbine typically includes combustors that are coupled to a stage-one nozzle of the turbine section via transition ducts. Generally, each transition duct has an aft frame positioned adjacent to an inlet side of the turbine section. The aft frame will usually have two arcuate portions which are referred to as inner and outer portions, being inner and outer in the radial direction with respect to the centerline axis of the turbine. The inner and outer portions of the aft frame are interconnected by radially extending linear portions, often referred to as side portions. A sealing assembly is typically used to seal between the aft frame and the inlet of the turbine section. In particular, inner and outer circumferential seals are used to seal between the inner and outer portions of the aft frame and the corresponding inlet of the turbine section. Likewise, radially oriented side seals can be disposed between adjacent aft frames to substantially close and seal off the circumferential gaps between the side portion of one aft frame and the next aft frame.

The sealing assembly positioned about the aft frame generally functions to prevent the high temperature combustion gases being diluted with compressed air prior to entrance into the turbine section.

However, issues exist with the use of many known sealing assemblies. For example, the high temperature of the combustion gases can cause damage to the sealing assembly over time, which may result in a limited life and decreased durability of the assembly. In addition, thermal expansion and vibrational movement of the aft frame and the stage one nozzle during operation of the gas turbine can cause the sealing assemblies to misalign and/or entirely decouple, which results in an incomplete seal between the components.

<CIT> describes a sealing device fitted and inserted into the grooves which are formed in the two adjacent members constituting the housing structure of a power device. The sealing device comprises two seal members that are disposed in the grooves and a partition member extending between the seal members. <CIT> discloses a gas turbine combustor which is equipped with a transition piece assembly. The transition piece assembly includes a transition piece and a frame which is installed on the downstream side of the transition piece and a seal member which is installed on a coupled part of the aforementioned frame and a turbine-side stator vane part. The seal member blocks flowing of compressed air from a compressor to a turbine side through a gap of the coupled part. <CIT> describes a seal assembly that can be positioned between a first surface and a second surface of a structure or vehicle. The seal assembly includes a geometric-shaped seal such as a bulb-shaped seal that can be secured to an outer perimeter of the first surface and a receiving land capture that can be secured to an outer perimeter of the second surface. The geometric-shaped seal is designed to engage with the receiving land capture, and join the first surface and second surface when the geometric-shaped seal is engaged with the receiving land capture.

Accordingly, an improved sealing assembly is desired in the art. In particular, an improved sealing assembly for a gas turbine engine that has increased durability and alignment is desired, thereby prolonging the overall life and durability of the sealing assembly.

Aspects and advantages of the sealing arrangements and gas turbine engine in accordance with the present invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the technology.

In accordance with one embodiment, a sealing arrangement for a gas turbine engine is provided. The sealing arrangement includes a first aft frame and a second aft frame neighboring one another. The first aft frame and the second aft frame each include an inner portion and an outer portion. The outer portion radially separated from the inner portion. The first aft frame and the second aft frame further include a first side portion and a second side portion that each extend radially between the inner portion and the outer portion. A circumferential gap is defined between the first side portion of the first aft frame and the second side portion of the second aft frame. The sealing arrangement further includes a side seal that extends across the circumferential gap. The side seal includes one or more magnets. The side seal is at least partially held in place by the one or more magnets.

In accordance with another embodiment, a gas turbine engine is provided. The gas turbine engine includes a compressor section, a turbine section, and a combustor section. The combustor section being positioned upstream from the turbine section and downstream from the compressor section. A first combustor and a second combustor neighbor one another within the combustor section. The first combustor and the second combustor each include a transition duct having an upstream end and a downstream end. A first aft frame surrounds the downstream end of the transition duct of the first combustor. A second aft frame surrounds the downstream end of the transition duct of the second combustor. The first aft frame and the second aft frame each include an inner portion and an outer portion radially separated from the inner portion. The first aft frame and the second aft frame each further include a first side portion and a second side portion that each extend radially between the inner portion and the outer portion. A circumferential gap is defined between the first side portion of the first aft frame and the second side portion of the second aft frame. The sealing arrangement further includes a side seal that extends across the circumferential gap. The side seal includes one or more magnets. The side seal is at least partially held in place by the one or more magnets.

These and other features, aspects and advantages of the present sealing arrangements and gas turbine engines will become better understood with reference to the following description and appended claims.

A full and enabling disclosure of the present sealing arrangements and gas turbine engines, including the best mode of making and using the present systems and methods, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:.

As used herein, the terms "upstream" (or "forward") and "downstream" (or "aft") refer to the relative direction with respect to fluid flow in a fluid pathway. The term "radially" refers to the relative direction that is substantially perpendicular to an axial centerline of a particular component, the term "axially" refers to the relative direction that is substantially parallel and/or coaxially aligned to an axial centerline of a particular component and the term "circumferentially" refers to the relative direction that extends around the axial centerline of a particular component. terms of approximation, such as "generally," or "about" include values within ten percent greater or less than the stated value. When used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction. For example, "generally vertical" includes directions within ten degrees of vertical in any direction, e.g., clockwise or counter-clockwise.

Referring now to the drawings, <FIG> illustrates a schematic diagram of one embodiment of a gas turbine <NUM>. Although an industrial or land-based gas turbine is shown and described herein, the present invention is not limited to a land based and/or industrial gas turbine unless otherwise specified in the claims. For example, the invention as described herein may be used in any type of turbomachine including but not limited to an aircraft gas turbine, or a marine gas turbine.

As shown, gas turbine <NUM> generally includes an inlet section <NUM>, a compressor section <NUM> disposed downstream of the inlet section <NUM>, a plurality of combustors (not shown) within a combustor section <NUM> disposed downstream of the compressor section <NUM>, a turbine section <NUM> disposed downstream of the combustor section <NUM>, and an exhaust section <NUM> disposed downstream of the turbine section <NUM>. Additionally, the gas turbine <NUM> may include one or more shafts <NUM> coupled between the compressor section <NUM> and the turbine section <NUM>.

The compressor section <NUM> may generally include a plurality of rotor disks <NUM> (one of which is shown) and a plurality of rotor blades <NUM> extending radially outwardly from and connected to each rotor disk <NUM>. Each rotor disk <NUM> in turn may be coupled to or form a portion of the shaft <NUM> that extends through the compressor section <NUM>.

The turbine section <NUM> may generally include a plurality of rotor disks <NUM> (one of which is shown) and a plurality of rotor blades <NUM> extending radially outwardly from and being interconnected to each rotor disk <NUM>. Each rotor disk <NUM> in turn may be coupled to or form a portion of the shaft <NUM> that extends through the turbine section <NUM>. The turbine section <NUM> further includes an outer casing <NUM> that circumferentially surrounds the portion of the shaft <NUM> and the rotor blades <NUM>, thereby at least partially defining a hot gas path <NUM> through the turbine section <NUM>.

During operation, a working fluid such as air <NUM> flows through the inlet section <NUM> and into the compressor section <NUM> where the air <NUM> is progressively compressed, thus providing pressurized air or compressed air <NUM> to the combustors <NUM> (<FIG>) of the combustor section <NUM>. The compressed air <NUM> is mixed with fuel <NUM> and burned within each combustor <NUM> (<FIG>) to produce combustion gases <NUM>. The combustion gases <NUM> flow through the hot gas path <NUM> from the combustor section <NUM> into the turbine section <NUM>, wherein energy (kinetic and/or thermal) is transferred from the combustion gases <NUM> to the rotor blades <NUM>, causing the shaft <NUM> to rotate. The mechanical rotational energy may then be used to power the compressor section <NUM> and/or to generate electricity. The combustion gases <NUM> exiting the turbine section <NUM> may then be exhausted from the gas turbine <NUM> via the exhaust section <NUM>.

As shown in <FIG>, a combustor <NUM> may be at least partially surrounded by an outer casing <NUM> such as a compressor discharge casing. The outer casing <NUM> may at least partially define a high-pressure plenum <NUM> that at least partially surrounds various components of the combustor <NUM>, such as transition duct <NUM>. The high-pressure plenum <NUM> may be in fluid communication with the compressor <NUM> (<FIG>) so as to receive the compressed air <NUM> therefrom. As illustrated in <FIG>, the combustor <NUM> may be connected to a stage-one nozzle <NUM> of turbine <NUM> via a transition duct <NUM> including an aft frame <NUM>. As shown in <FIG>, the aft frame <NUM> may define an aft face <NUM> and a forward face <NUM>. The transition duct <NUM> defines a flow path P. Also shown in <FIG> is the central axis A of turbine <NUM>, which defines an axial direction substantially parallel to and/or along axis A, a radial direction R (<FIG>) perpendicular to axis A, and a circumferential direction C (<FIG>) extending around axis A.

Referring now to <FIG>, a first transition duct <NUM> and a second transition duct <NUM> are illustrated, each having an upstream end <NUM> and a downstream end <NUM>. As shown, a first aft frame <NUM> surrounds the downstream end <NUM> of the first transition ducts <NUM>, and a second aft frame <NUM> surrounds the downstream end <NUM> of the second transition duct <NUM>. As illustrated in <FIG>, in some embodiments, the aft frames <NUM>, <NUM> may each include an inner portion <NUM> and an outer portion <NUM> radially separated from one another. A first side portion <NUM> and a second side portion <NUM> may extend radially between the inner and the outer portions <NUM> and <NUM>. For example, the transition ducts <NUM>, <NUM> may be arranged such that the first side portion <NUM> of the first aft frame <NUM> is spaced apart from the second side portion <NUM> of the second aft frame <NUM>, thereby defining a circumferential gap <NUM> therebetween. In many embodiments, the first side portion <NUM> of the first aft frame <NUM> and the second side portion <NUM> of the second aft frame <NUM> may be generally parallel to one another. Also illustrated in <FIG> is an inner seal <NUM> and an outer seal <NUM> respectively disposed on the inner portion <NUM> and outer portion <NUM> of each aft frame <NUM>. In some embodiments, as shown, the inner seal <NUM> and the outer seal <NUM> may each be a singular seal that extends in the circumferential direction continuously between the transition ducts <NUM>. In other embodiments, the inner seal <NUM> and the outer seal <NUM> may each be divided into one or more connected segments. In exemplary embodiments both the inner seal <NUM> and the outer seal <NUM> extend across (or traverse) the circumferential gap <NUM>, such that the side seal <NUM> is disposed radially between the inner seal <NUM> and the outer seal <NUM>.

As shown in <FIG>, inner seal <NUM> and outer seal <NUM> may be circumferentially oriented with respect to a circumferential direction C of the gas turbine <NUM>. For example, each inner seal <NUM> is circumferentially aligned with the other inner seal <NUM> on the adjacent aft frame <NUM>, and each outer seal <NUM> is circumferentially aligned with the other outer seal <NUM> on the adjacent aft frame <NUM>. Thus, inner seals <NUM> and outer seals <NUM> may be collectively referred to as circumferentially oriented seals.

In the description herein, certain features of the aft frames <NUM>, <NUM>, stage-one nozzle <NUM>, and seals, <NUM>, <NUM>, and <NUM>, will be described with reference to one or the other of inner portion <NUM>/inner seal <NUM> and outer portion <NUM>/outer seal <NUM>, nonetheless, it will be recognized by one of ordinary skill in the art that such features can be associated with either or both of inner portions <NUM> and/or outer portions <NUM>.

<FIG> illustrates a sealing arrangement <NUM>, in which the first aft frame <NUM> and the second aft frame <NUM> are enlarged to illustrate how the various seals <NUM>, <NUM>, <NUM> are arranged, in accordance with embodiments of the present invention. <FIG> illustrates a cross-sectional view of the sealing arrangement <NUM> shown in <FIG> from along an axial location that exposes the slots <NUM>, <NUM>, <NUM>, <NUM> (in which the seals <NUM>, <NUM>, <NUM> are held during operation). <FIG> illustrates a cross-sectional view of the sealing arrangement <NUM> shown in <FIG> at an axial location that exposes the internal configuration of the side seal <NUM>.

As shown in <FIG> collectively, the sealing arrangement <NUM> includes the first aft frame <NUM> and the second aft frame <NUM> neighboring one another. As discussed above in detail, the first aft frame <NUM> and the second aft frame may each include an inner portion <NUM> and an outer portion <NUM>. The inner portion <NUM> and the outer portion <NUM> may be spaced apart from one another and may co-extend in the circumferential direction C of the gas turbine <NUM>, such that the inner portion <NUM> and the outer portion <NUM> are generally curved to correspond with the circumferential direction C. In this way, when all of the combustors <NUM> are assembled in the combustion section <NUM>, the collective inner portions <NUM> of the aft frames <NUM> may define a segmented inner ring that extends around the centerline of the gas turbine <NUM> (along the circumferential direction C). Similarly, when all of the combustors <NUM> are assembled in the combustion section <NUM>, the collective outer portions <NUM> of the aft frames <NUM> may define a segmented outer ring that extends around the centerline of the gas turbine <NUM> (along the circumferential direction C).

The aft frames <NUM>, <NUM> may each include a first side portion <NUM> and a second side portion <NUM> spaced apart from one another and each extending between the inner portion <NUM> and outer portion <NUM>. In many embodiments, first side portion <NUM> and the second side portion <NUM> may each be substantially straight members that extend generally along the radial direction R of the gas turbine <NUM>.

In particular embodiments, as shown in <FIG> and <FIG>, the aft frames <NUM>, <NUM> may each define notches or slots <NUM>, <NUM>, <NUM>, <NUM> along a respective portion <NUM>, <NUM>, <NUM>, <NUM> of the aft frames <NUM>, <NUM> for partially receiving the seals <NUM>, <NUM>, <NUM>. For example, an outer slot <NUM> may be defined along the outer portion <NUM> of the aft frames <NUM>, <NUM> for partially receiving the outer seal <NUM>, and an inner slot <NUM> may be defined along the inner portion <NUM> of the aft frames <NUM>, <NUM> for partially receiving the inner seal <NUM>. Similarly, a first side slot <NUM> may be defined along the first side portion <NUM> of each of the aft frames <NUM>, <NUM> in order to partially receive a side seal <NUM>, and a second side slot <NUM> may be defined along a second side portion <NUM> of each of the aft frames <NUM>, <NUM> in order to partially receive the side seal <NUM>.

In some embodiments, the slots <NUM>, <NUM>, <NUM>, <NUM> may be interconnected such that they extend entirely around the perimeter of the respective aft frames <NUM>, <NUM> (e.g., the slots <NUM>, <NUM>, <NUM>, <NUM> may extend continuously through the side portions <NUM> and <NUM> and the inner and the outer portions <NUM> and <NUM>) for receiving both inner seal <NUM> and outer seal <NUM> as well a side seal <NUM> that is radially-oriented and provided between adjacent aft frames <NUM>, <NUM>. It is also possible in some embodiments to provide separate slots or notches for each of the seals <NUM>, <NUM>, and <NUM>, such that the slots <NUM>, <NUM>, <NUM>, <NUM> may be separately defined and not interconnected or continuous.

As shown in <FIG> and <FIG>, the first side portion <NUM> of the first aft frame <NUM> may neighbor (e.g. may directly neighbor or be immediately adjacent) the second side portion <NUM> of the second aft frame <NUM>, such that a circumferential gap <NUM> is defined the first side portion <NUM> of the first aft frame <NUM> and the second side portion <NUM> of the second aft frame <NUM>. In many embodiments, the first side portion <NUM> of the first aft frame <NUM> and the second side portion <NUM> of the second aft frame <NUM> may be generally parallel to one another, such that the circumferential gap <NUM> is equidistant at every radial location between the portions <NUM> and <NUM>.

In exemplary embodiments, as shown, both the outer seal <NUM> and the inner seal <NUM> each extend across the circumferential gap <NUM>. As a result, the outer seal <NUM> and the inner seal <NUM> create radially outer and inner boundaries within which the side seal <NUM> is contained. For example, the side seal <NUM> may extend radially between the outer seal <NUM> and the inner seal <NUM>.

As shown in <FIG>, a side seal <NUM> extends across the circumferential gap <NUM>, thereby preventing the combustion gases from being diluted with compressed air prior to entrance into the turbine section <NUM>. For example, the side seal may extend between the inner seal <NUM> and the outer seal <NUM>. In many embodiments, the side seal <NUM> may extend generally radially between the inner seal <NUM> and the outer seal <NUM> and across the circumferential gap <NUM>, which advantageously prevents compressed air from entering the hot gas path between the aft frames <NUM> and <NUM>.

In exemplary embodiments, as shown, the side seal <NUM> may extend from within the first side slot <NUM> defined in the first side portion <NUM> of the first aft frame <NUM>, across the circumferential gap <NUM>, to within the second side slot <NUM> defined in the second side portion <NUM> of the second aft frame <NUM>. The side seal <NUM> may be at least partially forced into sealing engagement with the first aft frame <NUM> and the second aft frame <NUM> by pressure from the compressed air within the high pressure plenum <NUM>, which produces a force on the side seal <NUM> in the axial direction A (i.e. out of the page in <FIG>).

In particular embodiments, the side seal <NUM> may further include a radially outer magnet <NUM>, a radially inner magnet <NUM>, and an outer shell <NUM>. The radially outer magnet <NUM> may couple (e.g. directly couple) to the outer seal <NUM>. For example, a first end <NUM> of the radially outer magnet <NUM> of the side seal <NUM> may magnetically couple to the outer seal <NUM> via an attractive magnetic force between the radially outer magnet <NUM> and the outer seal <NUM>. Likewise, the radially inner magnet <NUM> may couple (e.g. directly couple) to the inner seal <NUM>. For example, the first end <NUM> of the radially inner magnet <NUM> of the side seal <NUM> may magnetically couple to the inner seal <NUM> via an attractive magnetic force between the radially inner magnet <NUM> and the inner seal <NUM>. In this way, the side seal <NUM> may be at least partially held in place by the radially outer magnet <NUM> and the radially inner magnet <NUM>, which may advantageously allow for movement of the aft frames <NUM>, <NUM> during operation without misaligning the side seal <NUM>. In such embodiments, both the outer seal <NUM> and the inner seal <NUM> may be formed from a ferrous (or iron containing) metal, such that magnets <NUM>, <NUM> are attracted thereto.

For example, the radially inner seal <NUM>, the radially outer seal <NUM>, and the side seal <NUM> may be composed (at least partially) of a flexible sealing element, such as a ferrous (or non-ferrous in some embodiments) metallic cloth material. More specifically, the outer shell <NUM> of the side seal may be composed of the flexible sealing element. For example, the flexible sealing element may be a woven mesh cloth of a suitable metal material. The materials of the flexible sealing element may be layered, e.g., a single sheet of cloth material, may be folded over on itself, and/or multiple layers of cloth material may be welded together. In other embodiments (not shown), the inner seal <NUM> and the outer seal <NUM> may each include one or more permanent magnets that magnetically attract the respective radially inner magnet <NUM> and the respective radially outer magnet <NUM> thereto. In this way, the flexible sealing element may be a non-rigid compliant material that allows the seals <NUM>, <NUM>, <NUM> to bend and/or flex under loading during operation, which enables proper seal alignment at all thermal states of the combustors <NUM>.

The outer shell <NUM> of the side seal <NUM> may at least partially surround the radially inner magnet <NUM> and the radially outer magnet <NUM>. For example, the outer shell <NUM> may extend annularly around a portion of both magnets <NUM>, <NUM>, such that a portion of the magnets <NUM>, <NUM> are exposed (e.g. to compressed air and/or combustion gases). For example, as shown, the radially outer magnet <NUM> may extend radially outwardly from the outer shell <NUM> and magnetically couple directly to the outer seal <NUM>, and the radially inner magnet <NUM> may extend radially inwardly from the outer shell <NUM> and magnetically couple directly to the inner seal <NUM>. In other embodiments (not shown), the magnets <NUM>, <NUM> may be entirely encapsulated within the outer shell <NUM>, such that no portion of the magnets <NUM>, <NUM> are exposed (e.g. to compressed air and/or combustion gases).

In many embodiments, the radially outer magnet <NUM> and the radially inner magnet <NUM> may each include a first portion <NUM> and a second portion <NUM>. The first portion <NUM> may extend between respective first ends <NUM>, <NUM> and a respective transition point <NUM>, which is disposed between the first portion <NUM> and the second portion <NUM>. Likewise, each of the second portions <NUM> may extend from the respective transition point <NUM> to respective second free ends <NUM>, <NUM>. As shown, the first portion <NUM> may define a first width <NUM> and the respective second free ends <NUM>, <NUM> may define a second width <NUM>. As shown in <FIG>, the second width <NUM> may be larger than the first width <NUM>, such that the second portion <NUM> diverges circumferentially outwardly from the transition point <NUM> to the respective free ends <NUM>, <NUM> of the magnets <NUM>, <NUM>. For example, the magnets <NUM>, <NUM> may taper from the first width <NUM> to the second width <NUM>, in order to couple the magnets <NUM>, <NUM> to the interior surface <NUM> of the outer shell <NUM>.

In exemplary embodiments, the outer shell <NUM> may couple second portion <NUM> of the radially outer magnet <NUM> at a first end <NUM> and may couple to the second portion <NUM> of the radially inner magnet <NUM> at a second end <NUM>. In some embodiments, the outer shell <NUM> may be slidably coupled to the radially outer magnet <NUM> and the radially inner magnet <NUM>, such that radial movement of the aft frames <NUM>, <NUM> would result in the outer shell <NUM> sliding in the radial direction relative to the magnets <NUM>, <NUM>. In other embodiments, the interior surface <NUM> of the outer shell <NUM> may be fixedly coupled to both the magnets <NUM>, <NUM>, such that radial movement of the aft frames <NUM>, <NUM> would result in the outer shell <NUM> bending and/or flexing.

In many embodiments, the side seal <NUM> further includes a first side magnet <NUM> and a second side magnet <NUM> are positioned within the outer shell <NUM> of the side seal <NUM> opposite one another. For example, as shown, the first side magnet <NUM> and the second side magnet <NUM> may be coupled to an interior surface <NUM> of the outer shell <NUM>. In many embodiments, the first side magnet <NUM> and the second side magnet <NUM> may be substantially the same size (e.g. exactly the same size in some embodiments) and may be spaced apart from one another on opposite sides of the side seal <NUM>, in order to evenly distribute the repulsive magnetic forces <NUM>. For example, the first side magnet <NUM> may be positioned along (but spaced apart from by the outer shell <NUM>) the first side portion <NUM> of the first aft frame <NUM>. Similarly, the second side magnet <NUM> may be positioned along (but spaced apart from by the outer shell <NUM>) the second side portion <NUM> of the second aft frame <NUM>. In this way, the first side magnet <NUM> may be positioned at least partially within the first side slot <NUM>, and the second side magnet <NUM> may be positioned at least partially within the second side slot <NUM>. In other embodiments (not shown), the first side magnet <NUM> and the second side magnet <NUM> may each be a plurality of magnets connected to one another within the side seal <NUM>.

As shown in <FIG>, the first side magnet <NUM> and the second side magnet <NUM> may be arranged such that a repulsive magnetic force repels the first side magnet <NUM> and the second side magnet <NUM> away from one another and towards the respective slots <NUM>, <NUM>. As a result, the side seal <NUM> may be self-aligning in response to movements of the aft frames <NUM>, <NUM> (e.g. vibrational movements or thermal growth/contraction). In exemplary embodiments, the first side magnet <NUM> and the second side magnet <NUM> are disposed between the radially inner magnet <NUM> and the radially outer magnet <NUM> such that a repulsive magnetic force <NUM> repels the radially inner magnet <NUM> and the radially outer magnet <NUM> away from the first side magnet <NUM> and the second side magnet <NUM>. In many embodiments, all of the magnets <NUM>, <NUM>, <NUM>, and <NUM> of the side seal <NUM> may be spaced apart from one another and arranged to produce repulsive forces <NUM> with respect to one another. As a result, the side seal <NUM> may be self-aligning in response to movements of the aft frames <NUM>, <NUM>, thereby increasing the efficiency of the sealing arrangement <NUM>.

In the embodiment shown in <FIG>, the first side magnet <NUM> may be magnetically attracted to the first aft frame <NUM> via an attractive magnetic force. For example, the first side magnet <NUM> may be magnetically attracted to the first side portion <NUM> of the first aft frame <NUM>. Similarly, the second side magnet <NUM> may be magnetically attracted to the second aft frame <NUM>. For example, the second side magnet <NUM> may be magnetically attracted to the second side portion <NUM> of the second aft frame <NUM>. In such embodiments, the aft frames <NUM>, <NUM> may each be formed of a ferrous metal, such that the magnets are attracted thereto.

In other embodiments, such as the one shown in <FIG>, the aft frames <NUM>, <NUM> may each be formed of a non-ferrous metal or material, such that they are not impacted by magnetic forces. In such embodiments, as shown in <FIG>, the sealing arrangement <NUM> may further include a first aft frame magnet <NUM> is embedded within the first aft frame <NUM> and a second aft frame magnet <NUM> embedded within the second aft frame <NUM>. For example, the first aft frame magnet <NUM> may be embedded within the first side portion <NUM> of the first aft frame <NUM> and arranged such that it magnetically attracts the first side magnet <NUM>. Likewise, the second aft frame magnet <NUM> may be embedded within the second side portion <NUM> of the second aft frame <NUM> such that it magnetically attracts the second side magnet <NUM>. In this way, the first side magnet <NUM> may be magnetically attracted to the first aft frame magnet <NUM>, and the second side magnet <NUM> may be magnetically attracted to the second aft frame magnet <NUM>.

In many embodiments, each of the magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be in the form of a piece of metal material that has its component atoms so ordered that the material exhibits properties of magnetism, such as attracting other iron-containing objects or aligning itself in an external magnetic field. In exemplary embodiments, the magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be Alnico magnets, such that they are permanent magnets that are primarily made up of a combination of aluminum, nickel, and cobalt but may also include copper, iron and titanium. Alnico magnets may be capable of operation in extremely high temperatures, such as upwards of <NUM>, <NUM> (<NUM>° F).

In many embodiments, the magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may each include a first pole or north pole N and a second pole or south pole S. As is generally understood by those of skill in the art, the ends of a permanent magnet (such as the magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> described herein), are called its poles. One end is called the north pole, the other is called the south pole. If two magnets are oriented such the south pole of one faces the north pole of the other, the magnets will exhibit a force that pulls the magnets toward one other. Similarly, if two magnets are oriented such that two like poles are facing one another, the magnets will exhibit a force that repels the magnets away from one another. Although the magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are shown in <FIG> and <FIG> as having the poles labeled on specific ends, it is envisioned to be within the scope of the present invention that each of the poles may be switched, thereby yielding the same configuration but with an opposite magnetic pole orientation.

<FIG> illustrates a cross-sectional view of the sealing arrangement <NUM> from along a radial direction R. As shown, the first side slot <NUM> and the second side slot <NUM> may each include an aft wall <NUM>, a tapered forward wall <NUM>, and an axially extending side wall <NUM>. For example, the slots <NUM> and <NUM> may each be defined collectively by the walls <NUM>, <NUM>, <NUM>. In many embodiments the tapered forward wall <NUM> may allow the side seal <NUM> to be received by the slots <NUM> and <NUM> during the installation thereof (as illustrated by the dashed line and arrow in <FIG>). For example, the tapered forward wall <NUM> may be generally sloped with respect to the aft wall <NUM> and the axially extending side wall <NUM>.

In many embodiments, as shown in <FIG>, the side seal <NUM> may have a substantially rectangular cross-sectional shape (having the longest side oriented in the circumferential direction C when installed). In particular embodiments, as shown in <FIG>, the first aft frame magnet <NUM> may be embedded within the aft wall <NUM> and/or the axially extending side wall <NUM> of the first side portion <NUM> of the first aft frame <NUM>. Likewise, the second aft frame magnet <NUM> may be embedded within the aft wall <NUM> and/or the axially extending side wall of the second side portion <NUM> of the second aft frame <NUM>.

In operation, the sealing arrangement <NUM> described herein advantageously prevents combustion gases <NUM> from being diluted with compressed air prior to entrance into the turbine section <NUM>. The side seal <NUM> described herein may be advantageously self-aligning in response to movements (e.g. vibrational movements and/or thermal movements) of the aft frames <NUM>, <NUM> due to the various magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> exhibiting forces on the compliant outer shell <NUM> of the seal <NUM>.

Claim 1:
A sealing arrangement (<NUM>) for a gas turbine engine, , comprising:
a first aft frame (<NUM>) surrounding a downstream end (<NUM>) of a first transition duct (<NUM>) of a first combustor and a second aft frame (<NUM>) surrounding a downstream end (<NUM>) of a second transition duct (<NUM>) of a second combustor, the first aft frame (<NUM>) and the second aft frame (<NUM>) neighboring one another, the first aft frame (<NUM>) and the second aft frame (<NUM>) each comprising an inner portion (<NUM>) and an outer portion (<NUM>), the outer portion (<NUM>) radially separated from the inner portion (<NUM>), the first aft frame (<NUM>) and the second aft frame (<NUM>) each further comprising a first side portion (<NUM>) and a second side portion (<NUM>) that each extend radially between the inner portion (<NUM>) and the outer portion (<NUM>), wherein a circumferential gap (<NUM>) is defined between the first side portion (<NUM>) of the first aft frame (<NUM>) and the second side portion (<NUM>) of the second aft frame (<NUM>); and
a side seal (<NUM>) extending across the circumferential gap (<NUM>),
characterized in that the side seal (<NUM>) comprises one or more magnets, wherein the side seal (<NUM>) is at least partially held in place by the one or more magnets.