LINER FOR GAS TURBINE ENGINE

An embodiment of a gas turbine engine having a liner and casing is disclosed. The liner is disposed between the casing and a rotatable turbomachinery component. In one form, the rotatable turbomachinery component is a turbofan engine. The liner can be thin relative to a distance between the liner and the casing. Protrusions can be used between the liner and the casing. The protrusions can be a rib and can extend from the casing or the liner. An insert, such as an abradable surface, can be used with the liner. A filler can be used in the space between the liner and the casing.

TECHNICAL FIELD

The present disclosure generally relates to liner members for gas turbine engines. More particularly, but not exclusively, the present disclosure relates to configurations and orientations of liner members relative to casings of gas turbine engines.

BACKGROUND

Providing mechanisms to contend with blade out events, such as fan blade out events (FBO), remains an area of interest. Some liner systems employ honeycomb liners which can be used in the event of a blade rub or a blade out condition and, in these embodiments, a low density honeycomb can be used on the backside of an abradable lining that includes an epoxy filled honeycomb. Gas turbine engines can use these liners directly bonded to the inside of the fan case or in the form of a set of cassettes that are bolted into place. Fillers and/or sealants can be used between liner segments and at liner to casing interfaces. Some existing systems have various shortcomings relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.

SUMMARY

One embodiment of the present disclosure is a unique liner for a gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for liner systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the disclosure as described herein are contemplated as would normally occur to one skilled in the art to which the disclosure relates.

With reference toFIG. 1, a gas turbine engine50is illustrated having a compressor52, combustor54, and turbine56which together can be used to produce a useful power. Generally speaking, a working fluid such as air enters the gas turbine engine50whereupon it is compressed through action of the compressor before being mixed with a fuel and combusted in the combustor54. The turbine56is arranged to receive a flow from the combustor54and extract useful work from the flow. The gas turbine engine can be used to provide power to, for example, an aircraft. As used herein, the term “aircraft” includes, but is not limited to, helicopters, airplanes, unmanned space vehicles, fixed wing vehicles, variable wing vehicles, rotary wing vehicles, unmanned combat aerial vehicles, tailless aircraft, hover crafts, and other airborne and/or extraterrestrial (spacecraft) vehicles. Further, the present disclosures are contemplated for utilization in other applications that may not be coupled with an aircraft such as, for example, industrial applications, power generation, pumping sets, naval propulsion, weapon systems, security systems, perimeter defense/security systems, and the like known to one of ordinary skill in the art.

Turning now toFIG. 2, an embodiment of the gas turbine engine50is shown wherein a turbomachinery component in the form of a fan section58of a turbofan engine is illustrated. A pressure of a flow stream60is changed via operation of a fan62before the flow stream is split between a core flow64and bypass flow66. A casing68and a member70forming a liner surface (hereafter liner70whether or not the member is a single construction, unitary component, layered assembly of parts, etc. as is described further herein) are used near the fan62and are shaped to be useful during a Fan Blade Out (FBO) condition in which a portion of the fan62may penetrate the liner70and be contained by the casing68. The casing68includes a portion72directed away from a flow path through the fan section58and the liner70is situated between the casing68and the flow path. The liner70forms a flow path surface over which the flow stream is conveyed by operation of the gas turbine engine50. The portion72directed away from the flow path can take a variety of forms such as the c-shape disclosed in the illustrated embodiment, but other configurations of the recess that is formed are also contemplated herein.

Turning now toFIG. 3, a volume74is formed between the liner70and the casing that in some forms can be substantially annular in shape. The volume74can have substantially the same orientation/size/etc. circumferentially around the gas turbine engine50, but some variations are contemplated herein. For example, some structure(s) can be located within the volume74for any variety of purposes. The volume74generally has a depth d that in some embodiments, such as the illustrated embodiment, can vary from a forward end76to an aft end78of the volume74. The depth d is generally as large as or larger than a thickness t of the liner70, but smaller ranges are also contemplated in any of the various embodiments herein. In some forms the depth d is several times the size of the liner thickness t. In those cases where the depth d varies widely between the forward end76and aft end78, and/or in those cases where the thickness t varies widely between the forward end76and aft end78, the depth d can be as large or larger than the size of the liner thickness t over a relatively large range of the axial length of the volume74, and/or than the size of the thickness t in the area around the fan62. Such a characteristic can sometimes be referred to as a base thickness. To set forth just a few non-limiting examples, the depth d can be twice as large as or larger than the thickness t, where such larger variation can be any multiple, or intermediate multiple.

Lugs80can be provided to mount the liner70to the casing68. The lugs80can be formed in the casing68and in some forms are intermediate structure coupled to the casing68. The lugs80can take any suitable form, including flanges, etc., that are used to provide a supporting surface to which the liner70is affixed. The lugs80can be circumferentially formed surfaces, and, in some embodiments, the lugs80can be localized features at select circumferential locations. The forward and aft lugs80can take a similar form (integral with casing, coupled with casing, flanges, etc.), but in some embodiments the forward and aft lugs80can be different.

The liner70can be affixed to the casing68and/or the lugs80using any variety of techniques. For example, the liner70can be affixed relative to the casing68using mechanical fasteners such as bolts, screws, rivets, etc., and in some forms can be bonded to the casing68using chemical and/or metallurgical bonding techniques, such as adhesion bonding or welding, to set forth just a few non-limiting examples of affixing the liner70.

The manner in which the liner70is affixed, and alternatively and/or additionally the construction of the liner70, can determine the manner in which the liner70reacts when contacted by the fan62. It is generally contemplated that the liner70reacts by moving and/or removing at least a portion such that a space is created as a result of a trajectory of the fan62. Such a space can be permanently formed such as, for example, when the liner70yields to a reaction with the fan62. For example, the liner70can react to contact from the fan62by being frangible. In this example such a reaction can be determined by the construction of the liner70, such as, for example, whether it is constructed of a single material having ductile properties. In some embodiments, the liner70can react by rupturing at a contact area with the fan62, and in some forms can additionally and/or alternatively separate at one or more points where the liner70is affixed. In still further forms, the liner70can react by separating from the casing68and/or lugs80in lieu of permanently yielding. In still further forms, the liner70can be separated from the casing68through a combination of yielding and separating. Not all portions of the liner70need react when the fan62makes contact. For example, some portion of the liner70can remain behind after a contact. In short, any variety of dynamic impact reactions is contemplated.

The liner70of the illustrated embodiment generally extends around the circumferential annular flow space of the turbofan engine. The liner70can be segmented such that a series of liner constructions are distributed around the fan62. In those embodiments in which segments are used, not all segments need react to a blade contact. For example, when a Fan Blade Out occurrence causes a rotor imbalance in which the fan62orbits about an axis, certain circumferential locations of the liner70can react with the fan while other circumferential locations do not react with the fan. The segments can be similarly shaped, but in some embodiments not all segments need be similar to each other. A seal, such as a filler or sealant, can be used between circumferential segments. Additionally and/or alternatively, a seal can be used in the forward and aft portions of the liner70.

In one non-limiting embodiment, the volume74between the liner and the casing can be substantially empty. For example, the space can provide an annular volume of air. In some embodiments the volume74can be segregated in some fashion. In those embodiments, the segregated compartments can be substantially empty of any materials with the exception of air or other working fluid. In still further non-limiting embodiments, the volume74can include a low-density filler that could be used in some applications to increase stiffness and dampening. Such a filler could be located at one or more circumferential locations in the volume74, or alternatively be located throughout the volume74distributed around the fan62.

The liner70can be constructed in a variety of manners. For example, the liner70can be constructed as a single article or as an article that has portions fastened/bonded/etc. to one another. Such an article having portions connected to one another can take the form of a layered composition. The liner70can be cast, stamped, molded, or made in a composite construction. The liner70, furthermore, can be made of one or more materials such as metallic, plastic, composite, etc. In short, the liner70can take on any variety of constructions.

Turning now toFIG. 4, one non-limiting embodiment is shown of a liner70having an insert82which can be used in the event of a rubbing event with the fan62. Such an insert82can be an abradable material applied to the liner70using a variety of techniques whether mechanically fastened, cast, chemically or metallurgically bonded, spray coated, etc. The insert82can be any variety of depths and can extend any distance between the forward end76and aft end78. As shown in the illustrated embodiment, the insert82extends only partially between the forward end76and aft end78. In some forms the insert82is located in the area of the fan62.

One or more protrusion(s)84can extend between the casing68and the liner70, two non-limiting examples of which are shown inFIGS. 5 and 6. The protrusions84can take a variety of shapes, sizes, orientations, etc. and, in the illustrated embodiments, are shown generally as ribs that extend generally along a line. The protrusions84can be integrally formed with the structure from which it extends, but in some forms can be fastened using any variety of techniques. Furthermore, any number of protrusions84can be used in any given liner70.FIG. 5illustrates a number or protrusions84extending from the liner70toward the casing68and in which a gap is formed between the end of one or more protrusions84and the casing68. The gaps can be, but need not be, the same for each of the protrusions84. In some forms the gaps may not be present. A frictional interface can be used in some forms.FIG. 6illustrates protrusions84extending from the casing68and in which no gap is present with respect to the liner70. One or more gaps between the liner70and protrusions84could be formed in some embodiments.

In those embodiments that contain one or more protrusions from the backside of the liner70, the thickness t discussed above in regard to the depth d of the volume74can be considered the thickness t on either side of the protrusion(s). In this way the liner70can be said to have a base from which the protrusions extend, where the base includes the thickness t. In those embodiments where the thickness t varies over the length of the liner70, the protrusions can extend from locations other than the base. For example, the thickness t between the upstream end and downstream end of the liner70can vary, but generally, with the exception of intermediate structures such as the protrusions84, is substantially less than the depth d of the volume74created between the liner70and the casing68as discussed herein.

The volume74formed between the liner70and the casing68can be considered the volume between the casing and the liner70, whether or not the volume74includes a low density filler, etc. It will be understood that in those embodiments including protrusions84, the depth d of the volume74is generally the depth associated between the casing68and the liner70, and not the minimal distance, such as the gap shown inFIG. 5, between the protrusions84and the casing68.

Any of the various embodiments disclosed herein can be combined with other embodiments. For example, the insert82can be used with any of the various embodiments. For that matter, the protrusions84can be used in any of the various embodiments. Other combinations are also contemplated herein.

One aspect of the present application provides an apparatus comprising a gas turbine engine having a casing and a flow path located radially inward of the casing within which is disposed a rotatable turbomachinery component. The flow path is bounded by a construction that provides a liner surface located between the rotatable turbomachinery component and the casing. The construction has a base thickness between a flow path side and a non-flow path side which is smaller than an offset between the construction and the casing. The offset is free of the construction. The construction that provides the liner surface forms a flow path surface during a nominal mode of operation of the rotatable turbomachinery component. The construction that provides the liner surface is constructed to be sacrificial during an off-nominal mode of operation of the rotatable turbomachinery component such that a portion of the turbomachinery component can penetrate into an area free from the construction.

A feature of the present application provides wherein the rotatable turbomachinery component is a fan, and wherein an annular liner is formed that is constructed from a plurality of construction segments. Another feature of the present application provides wherein the construction that provides the liner surface is a single article that forms the flow path surface and is substantially free of internal voids.

Yet another feature of the present application provides wherein the construction includes a base portion and an abradable material adjacent the base portion. Still another feature of the present application provides wherein the off-nominal mode of operation includes an orbiting motion of the turbomachinery component, and wherein the gas turbine engine also including protrusions disposed in the area free from the construction.

Yet still another feature of the present application provides wherein the construction that provides the liner surface includes the protrusions. Still yet another feature of the present application provides wherein the area free from the construction includes a low density filler material. A further feature of the present application provides wherein the construction includes a plurality of materials.

Another aspect of the present application provides an apparatus comprising a gas turbine engine including a fan section having a rotatable fan blade portion structured to change a pressure of a working fluid flowing through a flow path of the fan section, a casing radially outward of the rotatable fan blade portion and having a shape the diverges from the flow path of the fan section, and a component having a liner surface radially inward from the casing to separate the casing from the rotatable fan blade portion. The component is offset from the casing to create a space free of a honeycomb structure intermediate the liner and the casing. The space is larger than a thickness of the component axially coincident with the rotatable fan blade portion.

A feature of the present application provides wherein the component is fixed relative to the casing through one of mechanical fastening or being bonded in place. Another feature of the present application provides wherein a coupling interface between the component and the casing is structured to fail and release the component when the fan blade portion contacts the component.

Yet another feature of the present application provides wherein the component is stamped sheet metal. Still another feature of the present application provides wherein the component is molded, and wherein the component is one of plastic and composite.

Yet still another feature of the present application provides wherein the component includes a solidity that substantially lacks internal voids. A further feature of the present application provides wherein liner includes a base plate and which further includes elongate portions that extend from between the back of the component and the casing. A still further feature of the present application provides wherein the space free of a honeycomb structure is an empty space.

Yet another aspect of the present application provides an apparatus comprising a gas turbine engine having a compressor rotatingly coupled with a turbine and a casing configured to enclose a bladed component of the gas turbine engine, and reaction means for ingressing a portion of the bladed component into a space formed between the casing and the reaction means. The reaction means is disposed between the casing and the bladed component to create a non-flow path volume. The reaction means having a predominate thickness extending between an upstream end and a downstream end. The non-flow path volume having a depth measured between the casing to the predominate thickness. The thickness of the reaction means is substantially smaller than the depth measured between the casing and the predominate thickness.

Still yet another aspect of the present application provides a method comprising a number of operations. The operations including rotating a bladed member of a gas turbine engine having a casing and a liner situated between the casing and the bladed member to create an area therebetween, the bladed member travelling along a nominal arc of rotation, impacting at least a portion of the bladed member with a liner located between the bladed member and a casing of the gas turbine engine, and reacting the liner with the portion of the bladed member to expose a volume formed by a placement of the liner relative to the casing, the liner providing an offset flow path surface for a working fluid from the casing.

A feature of the present application further includes penetrating the liner with the portion of the bladed member. Another feature of the present application provides wherein the reacting includes breaking the liner.

Yet another feature of the present application provides wherein the breaking includes removing at least a portion of the liner. Still another feature of the present application provides wherein the removing includes breaching a manner in which the liner is affixed relative to the casing. Yet still another feature of the present application provides wherein the breaching includes destroying a bond between the liner and the casing.