1. Technical Field
The disclosure generally relates to gas turbine engines.
2. Description of the Related Art
A typical gas turbine engine incorporates a compressor section and a turbine section, each of which includes rotatable blades and stationary vanes. Within a surrounding engine casing, the radial outermost tips of the blades are positioned in close proximity to outer air seals. The seals are parts of shroud assemblies mounted within the engine casing.
Each outer air seal typically incorporates multiple segments that are annularly arranged within the engine casing. In order to reduce gas leakage between adjacent segments, feather seals commonly are used. Typically, feather seals are configured as elongated strips of metal that are mounted within corresponding recesses located along adjacent ends of the segments. Thus, a feather seal is typically positioned between each pair of ends of adjacent segments.
Feather seals and gas turbine engine systems involving such seals are provided. In this regard, an exemplary embodiment of a feather seal for a gas turbine engine comprises: an elongate body portion; and a locating tab extending longitudinally along the body portion and extending outwardly therefrom.
An exemplary embodiment of an outer air seal assembly for a gas turbine engine comprises: a first outer air seal segment having a first sealing surface and a first end; a second outer air seal segment having a second sealing surface and a second end; the first outer air seal segment and the second outer air seal segment being oriented in an end-to-end annular arrangement such that the first end and the second end define a gap therebetween; and a feather seal having an elongate body portion and a locating tab extending outwardly from the body portion, the body portion having a first sealing surface and a second sealing surface, the locating tab being positioned between the first sealing surface and the second sealing surface such that, in an operative position in which the first sealing surface of the feather seal contacts the first sealing surface of the outer air seal and the second sealing surface of the feather seal contacts the second sealing surface of the outer air seal, the locating tab extends into the gap and between the first outer air seal segment and the second outer air seal segment.
An exemplary embodiment of a gas turbine engine comprises: a compressor; a combustion section; a turbine operative to drive the compressor responsive to energy imparted thereto by the combustion section, the turbine having a rotatable blade; and an outer air seal assembly annularly arranged about the turbine, at least a portion of the outer air seal being located radially outboard of the blade, the outer air seal assembly comprising: a first outer air seal segment; a second outer air seal segment; and a feather seal having an elongate body portion and a locating tab extending longitudinally along the body portion and extending outwardly therefrom; the first outer air seal segment and the second outer air seal segment being oriented in an end-to-end annular arrangement such that the first end and the second end define a gap therebetween, the locating tab extending into the gap.
Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Feather seals and gas turbine engine systems involving such seals are provided, several exemplary embodiments of which will be described in detail. In this regard, the feather seals incorporate locating features that tend to position the seals between adjacent outer air seal segments. In some embodiments, the locating feature is oriented along a centerline of the seal, with the seal generally exhibiting a T-shape when viewed along an end view. Such a configuration potentially enables the width of the feather seal to be reduced, which can reduce component weight. This can also potentially alleviate the difficulty associated with cooling outer air seals that use wider feather seals. This is because the wider feather seals tend to cover more of the outer air seal segments and thereby limit the locations where cooling holes can be formed in those segments. In some embodiments, the locating feature can serve as a bumper that prevents part-to-part contact of adjacent outer air seal segments. Notably, such part-to-part contact is conventionally accommodated by machining bumpers into the segments themselves, which oftentimes requires the use of additional material and a corresponding machining step.
Referring now in more detail to the drawings,
A portion of engine 100 is depicted in greater detail in the schematic diagram of
As shown in
Attachment of the outer air seal to the mounting ring in the embodiment of
With respect to the annular configuration of the outer air seal, outer air seal 124 is formed of multiple arcuate segments, portions of two of which are depicted schematically in
In operation, relatively high pressure (PHIGH) gas located radially outboard of feather seal 250 causes the sealing surfaces 262, 264 to contact corresponding surfaces (e.g., surfaces 266, 268) of the outer air seal segments, thereby forming an air seal. Notably, locating tab 256 extends between the outer air seal segments.
In the embodiment of
The locating tab functions as a stop that inhibits lateral movement of the feather seal. Specifically, movement of the feather seal is prevented in a direction A (
Additionally, a locating tab can function as a bumper that inhibits physical contact between adjacent out air seal segments in a vicinity of the locating tab. Without such a locating tab extending between adjacent segments, the gap between the segments may become too narrow, thereby preventing an adequate flow of cooling air from flowing through the gap.
In some embodiments (see
It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims.
The U.S. Government may have an interest in the subject matter of this disclosure as provided for by the terms of contract number F-33615-03-D-2354 (DO 0009) awarded by the United States Air Force.