Patent Application
20120148406
The inventive subject matter generally relates to gas turbine engines, and more particularly relates to turbine rotor assemblies for use in gas turbine engines.
Gas turbine engines, such as turbofan gas turbine engines, may be used to power various types of vehicles and systems including, for example, aircraft. Typically, these engines include turbine blades that are impinged on by high-energy compressed air that causes a turbine of the engine to rotate at a high speed. Consequently, the blades are subjected to high heat and stress loadings which, over time, may reduce their structural integrity.
To improve blade structural integrity, a blade cooling scheme is typically incorporated into the turbines. The blade cooling scheme directs cooling air through an internal cooling circuit formed in the blade to maintain blade temperatures within acceptable limits. The internal cooling circuit may include a simple channel extending through a length of the blade or may consist of a series of connected, serpentine cooling passages, which incorporate raised or depressed structures therein. The serpentine cooling passages increase the cooling effectiveness by extending the length of the air flow path. In this regard, the blade may have multiple internal walls that form the intricate cooling passages through which the cooling air flows. The cooling passages then direct the cooling air to openings at the tip, trailing edge, or elsewhere on the blade.
As the desire for increased engine efficiency continues to rise, engine components are increasingly being subjected to higher and higher operating temperatures. For example, newer engine designs may employ operating temperatures that are about 150° C. higher than conventional operating temperatures. However, currently designed engine components, such as the blades, may not be sufficiently designed to withstand such operating temperatures. In an example, certain portions of the blade, such as a platform of the blade, may draw cooling air from the internal cooling circuit, but may not be adequately cooled by the drawn cooling air. Moreover, the cooling air from the internal cooling circuit used to cool the platform can cause an increase in system pressure loss. As a result, engine efficiency is decreased. Additionally, in an event in which a structure of the internal cooling circuit is compromised, platform cooling may be adversely affected.
Accordingly, it is desirable to have an improved system for cooling a blade. In addition, it is desirable for the improved system to adequately cool the blade platform with minimal cooling flow and pressure loss. Furthermore, other desirable features and characteristics of the inventive subject matter will become apparent from the subsequent detailed description of the inventive subject matter and the appended claims, taken in conjunction with the accompanying drawings and this background of the inventive subject matter.
In an embodiment, by way of example only, a turbine rotor disk is provided. The turbine rotor disk includes a hub, a ring attached to the hub, the ring including a plurality of posts extending radially outwardly and disposed around a circumference of the ring, each post including a first radially-extending face, a second radially-extending face, and a blade attachment surface extending axially between the first and second radially-extending faces, a main cooling air feed channel formed in each post and extending from the first radially-extending face toward the second radially-extending face, and a plurality of ancillary jet openings formed in each post and extending from the main cooling air feed channel to the blade attachment surface.
In another embodiment, by way of example only, a turbine assembly is provided that includes a disk including a hub and a ring attached to the hub, the ring including a plurality of posts extending radially outwardly and disposed around a circumference of the ring to define a plurality of blade attachment slots, each post including a first radially-extending face, a second radially-extending face, and a blade attachment surface extending axially between the first and second radially-extending faces, a main cooling air feed channel formed in each post and extending from the first radially-extending face toward the second radially-extending face, and a plurality of ancillary jet openings formed in each post and extending from the main cooling air feed channel to the blade attachment surface, and a plurality of blades disposed in corresponding slots of the plurality of blade attachment slots, each blade including an airfoil, a root, and a platform, the platform supporting the airfoil and having an airfoil-facing wall and a root-facing wall, the root-facing wall defining a cooling cavity with the blade attachment surface for receiving cooling air from the plurality of ancillary jet openings.
The inventive subject matter will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
The following detailed description is merely exemplary in nature and is not intended to limit the inventive subject matter or the application and uses of the inventive subject matter. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
An improved turbine disk is provided that contributes to cooling a platform for a blade. The improved turbine disk has a hub and a ring attached to the hub, where the ring includes a plurality of posts extending radially outwardly and disposed around a circumference of the ring, each post defined by a first radially-extending face, a second radially-extending face, and a blade attachment surface, the blade attachment surface extending axially between the first and second radially-extending faces, each post including a main cooling air feed channel and a plurality of ancillary jet openings, the main cooling air feed channel extending between the first radially-extending face the second radially-extending face, and the plurality of ancillary jet openings extending from the main cooling air feed channel to the blade attachment surface. Cooling air is directed into the main cooling air feed channel and out of the plurality of ancillary jet openings, which are angled to flow the cooling air toward particular locations on an underside of the platform of the blade.
The cooling air source provides relatively cool air to the cooling air cavity 218 via a series of passages. The passages are formed in each post 202 of the disk 200 and comprise a main cooling air feed channel 230 and a plurality of ancillary jet openings 232, 234. The main cooling air feed channel 230 extends from the first radially-extending face 206 toward the second radially-extending face 208. Generally, the main cooling air feed channel 230 does not fully extend from the first radially-extending face 206 to the second radially-extending face 208. For example, the main cooling air feed channel 230 can include an inlet 236 formed on the first radially-extending face 206. The plurality of ancillary jet openings 232, 234 serve as outlets for the flow of the cooling air. In the depicted embodiment, the inlet 236 of the main cooling air feed channel 230 is located on the first radially-extending face 206 of the disk 200. In another embodiment, the inlet 236 is located on the second radially-extending face 208 of the disk 200.
The plurality of ancillary jet openings 332, 334 are arranged to distribute cooling air to different parts of a cooling air cavity (e.g., cooling air cavity 218 in
Each opening of the second set of ancillary jet openings 334 extends along corresponding third axes 344 that are disposed at angles within a second range of angles relative to the first axis 338, where the third axes 344 extend in directions that are different from those of the second axes 340. The third axes 344 may or may not intersect the first and/or second axes 338, 340. In any case, the second range of angles includes angles in a range of about 0° to about 45°, in an embodiment. In other embodiments, the angles in the second range of angles include values that are greater or less than ones that fall within the aforementioned range. Although the openings are shown to be substantially similarly disposed relative to the first axis 338, two or more openings of the second set of ancillary jet openings 334 can be disposed at two or more angles relative to the first axis 338.
The total number of ancillary jet openings 332, 334 varies depending on size and shape of the post 302. Hence, although ten total jet openings 332, 334 are depicted in
As noted above, the inlet for the cooling air can be provided on a surface serving as either the forward or the aft surface of the post 302. In this regard, the components adjacent to the post 302 (e.g., turbine blades and/or sealing plates) are configured to direct cooling airflow to locations of the post 302 within which the main cooling air feed channel 330 are formed.
The annular sealing flange 414 extends axially from the forward seal plate 404 and is configured to seal against a root (not shown) of a corresponding blade 402 in the turbine rotor disk 406. In this regard, the annular sealing flange 414 is disposed radially inward from an outer diameter 417 of the forward seal plate 404. In an embodiment, the annular sealing flange 414 has a relatively flat sealing surface 420 for contacting the blade 402. The sealing flange 414 can include a sealing ring 418 formed in a suitably located groove 422 in the annular sealing flange 414 to improve sealing. The cooling air from the flow cavity 408 is directed to the blade 402 for direction into an inlet 429 of a main cooling air feed channel 431 formed in a post 433 of the disk 406 and out ancillary jet openings 435 in flow communication with the main cooling air feed channel 431. The inlet 429 is formed on a forward surface (i.e., first radially-extending face 424) of the post 433. To provide the outer radial cavity 412 (and thus, the main cooling air feed channel 431 and ancillary jet openings 435) with the cooling air, a delivery channel 440 is formed through the forward seal plate 404. In an embodiment, the delivery channel 440 extends behind the groove 422 of the forward seal plate 404. Although a single delivery channel 440 is included in
Spent cooling air exits through a gap 450 defined, in part, by an underside 452 of a platform 454 of the blade 402. In this regard, an outermost radial section of the aft seal plate 405 is configured to be located radially inward from the platform 454 of the blade 402. Alternatively, the delivery channel is formed through a root of the blade 402, which is disposed in a blade attachment slot of the turbine rotor disk 406. Because an inner radial surface of the root is spaced apart from the surface defining the blade attachment slot to form a flow channel, the delivery channel can extend from the flow channel to a leading side wall of the root and to flow cooling air from the flow channel into the outer radial cavity 412.
The annular sealing flange 614 extends axially from the aft seal plate 605 and is configured to seal against a root (not shown) of a corresponding blade 602 in the turbine rotor disk 606. In this regard, the annular sealing flange 614 is disposed radially inward from an outer diameter 617 of the aft seal plate 605. In an embodiment, the annular sealing flange 614 has a relatively flat sealing surface 620 for contacting the blade 602. The sealing flange 614 can include a sealing ring 618 formed in a suitably located groove 622 in the annular sealing flange 614 to improve sealing. The cooling air from the flow cavity 608 is directed to the blade 602 for direction into an inlet 629 of a main cooling air feed channel 631 formed in a post 633 of the disk 606 and out ancillary jet openings 635 in flow communication with the main cooling air feed channel 631. The inlet 629 is formed on an aft surface (i.e., second radially-extending face 607) of the post 633. To provide the outer radial cavity 612 (and thus, the main cooling air feed channel 631 and ancillary jet openings 635) with the cooling air, a delivery channel 640 is formed through the aft seal plate 605. In an embodiment, the delivery channel 640 extends behind the groove 622 of the aft seal plate 605. Although a single delivery channel 640 is included in
Spent cooling air exits through a gap 650 defined, in part, by an underside 652 of a platform 654 of the blade 602. In this regard, an outermost radial section of the forward seal plate 604 is configured to be located radially inward from the platform 654 of the blade 602. Alternatively, the delivery channel is formed through a root of the blade 602, which is disposed in a blade attachment slot of the turbine rotor disk 606. Because an inner radial surface of the root is spaced apart from the surface defining the blade attachment slot to form a flow channel, the delivery channel can extend from the flow channel to a leading side wall of the root and to flow cooling air from the flow channel into the outer radial cavity 612.
Improved turbine rotor disks and turbine rotor assemblies have now been provided. By including a main cooling air feed channel and a plurality of ancillary jet openings in the posts of a turbine rotor disk, improved cooling of a platform of a blade can be achieved. The main cooling air feed channel can have an inlet formed in either the forward or aft sides of the turbine rotor disk to thereby provide flexibility to the design of the turbine rotor assemblies.
While at least one exemplary embodiment has been presented in the foregoing detailed description of the inventive subject matter, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the inventive subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the inventive subject matter. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the inventive subject matter as set forth in the appended claims.
