Core assembly and blade assembly using the same, and cooling flow path forming method

The present invention generally relates to cooling channels for blades. In particular, the present invention relates to a core assembly that forms a cooling flow path for a wing.

The US Government may have some rights in the present invention under Contract No. N00019-02-C-3003 ordered by the US Navy.

Generally, a gas turbine engine comprises a plurality of turbine blades that convert energy from the mainstream of combustion gas into mechanical energy that rotates and drives a compressor. Each turbine blade comprises a wing that produces rotational energy that is desired to drive the compressor from the flow of main combustion gas.

The turbine blade assembly is exposed to the hot combustion gas exhausted from the combustor of the gas turbine engine. The temperature of the combustion gas exhausted through and onto the turbine blade assembly can reduce the useful life of the turbine blade assembly. For this reason, each turbine blade is provided with a plurality of cooling air channels. Cooling air is sent through each of the turbine blades and exhausted through film holes on the surface of the turbine blades. The location of the film holes on the surface of the turbine blades creates a layer of cooling air on the surface of the turbine blades. The cooling air insulates the turbine blades from the hot combustion gas. Insulating the turbine blades from exposure to hot combustion gases significantly improves the reliability and service life of the turbine blades.

Generally, the cooling flow path in the turbine blades is formed by a ceramic core, which core is provided with and surrounded by a molten material used to form the turbine blades. Once the molten material used to form the turbine blades has solidified, the core material is removed. When the core material is removed, the required cooling air flow path is left with the required shape of the film cooling holes.

As is obvious, each turbine blade assembly represents a dead end, or end of the cooling air flow path. This is because the cooling air flowing from the inner side surface or the platform of the turbine blade flows radially outward toward the tip of the turbine blade. The tip of the turbine blade is closed to form the end of the cooling air flow path. Therefore, the only outlet for cooling air through the turbine blades passes through a plurality of film cooling holes arranged on and around the turbine blade surface. The composition and quantity of film holes that cool the turbine blades are determined to produce the required flow rate of cooling air.

The shape of the turbine blades varies throughout the cross section of the turbine blades from the front edge to the trailing edge. The front edge is most often much thicker than the trailing edge. However, the need for cooling at the trailing edge is often greater than at the leading edge, so the cooling channels need to be placed close to the trailing edge. As is clear, the cooling channels within the thin edge section are very small. This small cooling channel requires a small core assembly to form these cooling channels. As the size of the core assembly decreases, it becomes more vulnerable to damage during the molding process. Small core assemblies require the required cooling channels in the thin parts of the turbine blades and are more vulnerable to damage during manufacturing.

<p> Therefore, it is desirable to develop a robust core assembly that provides reliable manufacturing process results while achieving the formation of small cooling air channels in the thin sections of the turbine blade assembly.</p><p> Another problem with the structure and configuration of the cooling air flow path is the direction of the cooling air on the inner surface of the cooling air flow path. Generally, the cooling channel receives air from the main core. The main core of the turbine blades then communicates with the cooling air source. Therefore, the cooling air flow path includes an inner surface adjacent to the main core and an outer surface adjacent to the outer surface of the turbine blades. Collision holes (impingement holes) in the cooling air flow path allow air from the main core to communicate in the cooling air flow path and against its outer surface.</p><p> Therefore, it is desirable to develop a core assembly that forms the cooling air flow path within the turbine blade assembly that is reliable during the manufacturing process and provides the required cooling airflow characteristics that maximize heat transfer capacity utilization.</p>

<p> A typical embodiment of the present invention comprises a turbine blade assembly having cooling channels in which each of the collision holes is isolated from at least a portion of the other collision holes. Isolation of the collision holes in the cooling channel provides the direction of the cooling air flow to a particular required site. In addition, the core assembly used to form the cooling air flow path provides a series of structural members that enhance and improve productivity.</p><p> In the turbine blade assembly of the example of the present invention, a cooling air flow path communicating with the main core is formed. The main core then communicates with the cooling air from other systems. This cooling channel is formed using a unique core assembly with multiple collision holes isolated from each other. Isolating each of the collision holes from at least a portion of the other collision holes prevents orthogonal flow between the collision holes and improves the cooling air flow to the outer surface of the cooling flow path.</p><p> The core assembly provides a structure of the cooling flow path, and the core assembly comprises a collision structure member forming a collision opening. Each of the collision structural members is isolated from at least some of the other structural members by the separate structural member. The separation structure member forms a channel in the cooling flow path that isolates the collision opening. Each of the channels formed by the core assembly communicates with the expansion chamber on the side of the cooling flow path. Within the expansion chamber is a film structural member that is provided to create a film opening between the cooling air flow path and the outer surface of the turbine blade assembly.</p><p> Therefore, the turbine blade assembly of the present invention includes a cooling air flow path that provides the required cooling characteristics for the turbine blades.</p><p> These and other features of the invention are best understood from the following description and the drawings briefly described below.</p>

With reference to FIGS. 1A and 1B, the turbine blade assembly 10 includes a wing portion 12, a root portion 14, and a platform portion 16. The root portion 14 extends into a hub portion (not shown), as is known in the art. The root portion 14 extends to the platform portion 16. The wing 12 extends upward from the platform portion 16. The turbine blade portion 12 extends from the platform portion 16 to the tip 18. The turbine blade assembly 10 includes a front edge 20 and a trailing edge 22. There is an outer surface 24 between the leading edge 20 and the trailing edge 22. The outer surface 24 is shaped so that the flow of gas flow is transferred or converted into mechanical rotational energy. As will be appreciated, the turbine blade assembly 10 is known to those skilled in the art, as shown in FIG. 1A. Those competent in the art who will benefit from this disclosure will find that other wing configurations used in a variety of applications will also benefit from the disclosures of the present invention and the cooling channels.

The turbine blade assembly 10 includes a cooling flow path 30. The cooling flow path 30 is arranged in the turbine blade assembly 10. Cooling air enters the turbine blade assembly 10 through the flow path 26 in the root portion 14. The cooling air flows into the main core 28 (FIG. 1B) through the flow path 26. The main core 28 is a hollow portion inside the turbine blade assembly 10. Cooling air communicating through the flow path 26 into the main core 28 enters the cooling flow path 30 disposed in the turbine blade assembly 10. Cooling air enters the cooling flow path 30 from the main core 28 through the plurality of collision openings 32.

The cooling air flow from the collision opening 32 flows toward the expansion chamber 42 disposed on the opposite side of the collision opening 32. The cooling air flow passes through the walls of the turbine blade assembly 10 and through the film opening 34. The cooling air flowing out of the cooling flow path 30 through the film opening 34 flows over the outer surface 24 of the turbine blade assembly 10 to form a layer of cooling and insulation of the air.

The turbine blade assembly 10 of the present invention includes a cooling flow path 30. Each of the cooling channels 30 includes a collision opening 32. The collision openings 32 are isolated from each other by channels 36. The channel 36 is formed by a series of separated structural members 38. By separating and insulating each of the collision openings 32, it is possible to separate the cooling flow that collides with the outer surface of the cooling flow path 30. In addition, the isolation of the adjacent collision openings 32 prevents and reduces the problem of orthogonal flow that occurs in typical prior art collision openings. The flow from the collision opening 32 is sent through the channel 36 to the plurality of film holes 34. The film hole 34 communicates with the expansion chamber 42. The expansion chamber 42 forms part of the cooling flow path and retains the cooling air that will be communicated to the film holes 34. By retaining the cooling air in the expansion chamber 42, the problems associated with backflow collision with the wall corresponding to the collision opening 32 are reduced.

With reference to FIG. 2, a perspective view of the wing 12 is shown and the configuration of the main core 28 is illustrated. The main core 28 provides communication of cooling air that rises through the central portion of the turbine blade assembly 10 and communicates with the cooling flow path 30. The particular shape and configuration of the turbine blade assembly and blade 12 illustrated in FIG. 2 are known. Those who benefit from this disclosure will understand that many different types of wing configurations benefit from the cooling channel configurations illustrated and described within this disclosure.

Referring to FIG. 3, the cooling flow path 30 is formed in the turbine blade assembly 10 with the core assembly 44. The core assembly 44 can realize various configurations and structures including cooling flow path openings and channels during the fabrication of the turbine blade assembly 10. Traditionally, the turbine blade assembly 10 has been manufactured through a conventional molding process. The core assembly 44 can be made from known core materials such as specially formulated ceramics and cemented carbide. The core assembly 44 is placed in the mold and then surrounded by the molten material that makes up the turbine blade assembly 10. Once the material forming the turbine blade assembly 10 has solidified, the core assembly 44 is removed. Removal of the core assembly 44 is known and can consist of a variety of steps, including leeching or oxidation steps in which chemicals are used to disrupt and elute and separate the core assembly 44. .. As will be apparent, those skilled in the art who will benefit from this disclosure will understand that the use of other known molding steps and other materials falls within the intent and scope of the invention. .. The method of removal process used to remove the core 44 from the turbine blade assembly 10 depends on a variety of factors. These factors include the type of turbine blade material, the type of core material used, and the specific configuration of the cooling air flow path.

The core assembly 44, which is used to form a complex cooling air flow path, is needed to impart the desired cooling characteristics within the turbine blade assembly 10. The core assembly 44 comprises a collision structural member 46 extending into the completed turbine assembly 10 to form a collision opening 32. The core assembly 44 also includes a separating structural member 48 that forms the channels and walls needed to isolate each of the collision openings 32 from at least one other of the collision openings 32.

With reference to FIG. 4, a wing 12 is shown, of which a portion of its surface has been removed to illustrate certain functional members of the cooling air flow path formed therein. The cooling air flow path 30 includes expansion chambers 42 on both sides of the cooling air flow path 30. The cooling air flow path 30 includes a front edge side surface 50 and a trailing edge side surface 52. Each side of the cooling air flow path 30 comprises an expansion chamber 42. The adjacent collision opening 32 communicates with an expansion chamber 42 disposed on the opposite side of the cooling air flow path 30. Two adjacent collision openings do not allow cooling air to flow into the common expansion chamber 42. In this way, specific airflows can be controlled and regulated to cool specific parts and functional members of the wing 12.

Referring to FIG. 5, an example of the core assembly 44 is shown, which comprises a collision structural member 46 used to form a collision opening 32 within the wing 12. The collision opening 32 communicates cooling air from the main core 28 into the cooling flow path 30. The core assembly 44 also comprises a separation structural member 48 that is used and provided to separate the cooling air through the adjacent collision openings 32, respectively. The core assembly 44 has a structure opposite to that formed within the finished turbine blade blade 12. Thus, the collision structural member 46 is an extension member that extends through the blade 12 and forms an opening through the blade 12 to the main core 28. The structure and space of the core assembly 44 provides an open space within the completed wing 12.

The core assembly 44 includes a plurality of heat transfer promoting functional members 60. In these heat transfer promoting function members 60, in the completed cooling air flow path 30, the heat transfer promoting function member 60 forms a plurality of ridges extending upward in various cooling air flow paths 30. It is formed in the core assembly 44 as an opening. Those who benefit from this disclosure will also understand that heat transfer promoting functional members 60 of various shapes other than the illustrated examples that interrupt or send airflow are also within the intent of the present invention.

With reference to FIG. 6, the outer side surface 56 is illustrated. The outer side surface 56 is cut from the wing 12 illustrated in FIG. The outer side 56 is an integral part of the wing 12, although it is not generally sectioned as shown in FIG. The outer side surface 56 is adjacent to the outer surface of the wing 12. FIG. 4 illustrates the internal side surface 54 of the cooling flow path 30. The internal surface is adjacent to the main core 28. For this purpose, a raised portion 62 is provided on the outer side surface 56 illustrated in FIG. As is clear, thermal energy dissipates along the outer surface 24.

The outer side surface 56 adjacent to the outer portion of the wing 12 is provided on the side surface so that the cooling air flow has the greatest effect on the desired endotherm and heat transfer. The airflow through the collision opening 32 collides with the outer side surface 56 directly opposite the collision opening 32. The airflow then travels towards the expansion chamber 42 and directed by the channel 36 towards the anterior or posterior edge. Through channel 36, air is controlled and regulated to produce turbulent action that improves heat transfer and endothermic properties. Once the air reaches the expansion chamber 42, it stays and is exhausted through the film holes 34. The air is then exhausted into the main combustion gas stream through the film holes 34. The core assembly 44 of this embodiment is substantially linear. However, the core assembly 44 can include curved shapes to suit specific blade shape applications.

With reference to FIG. 7, a portion of the core assembly 44 that realizes the formation of the outer side surface 56 of the cooling air flow path 30 is shown. The core assembly 44 includes structural parts that form channels 36, film holes 34, and separation structural members 38. The collision structural member 46 is illustrated with a dashed line to indicate that it does not extend outward from this side surface of the core 44. Instead, the collision opening is formed from an extension member or structural member 46 that extends from the opposite side of the core. This aspect of the core assembly 44 produces these functional members within the outer aspect 56 of the cooling air flow path 30 of the completed wing 12. In the core assembly 44 of this embodiment, each collision structural member 46 opens into a separation channel 36. Therefore, each of the collision openings 32 is isolated from any of the adjacent collision openings 32. Within each channel, there are a plurality of heat transfer promoting structural members 60, which form a desired ridge and a heat transfer ridge 62 within the completed channel 36. The heat transfer structural member 60 illustrated in FIG. 7 is a cavity that receives material during the molding process in order to form an outwardly extending ridge.

With reference to FIG. 8, an internal side surface of the core assembly 44 is shown, which side surface comprises a collision structural member 46. The separated structural member 48 is shown by a dashed line to indicate that it does not extend from this side surface but extends from the opposite side surface. Moreover, other structural members formed on the inner side surface 54 to the outer side surface 56 are not shown for clarity. However, as is clear, these functional members extend outward from the opposite side and can also be represented by dashed lines in this drawing.

Referring to FIGS. 9 and 10, another example core assembly 70 according to the present invention comprises a plurality of collision structural members 46 disposed within the separation channel 36. In this core assembly 70, three collision structural members 46 are arranged in each separation channel 36. By providing some collision opening to each chamber, a particular air flow required amount Oyo collisions beauty cooling air flow on a particular site, so as to correspond to a site-specific heat transfer and heat absorption requirements Can be adjusted. However, there are several collision openings 46 disposed within each channel 36. These openings are isolated from at least one other collision opening, and the other collision openings are further isolated from at least one other collision opening. In addition, all collision openings are arranged around the centerline 40.

Each of the collision openings 32 is located around a common centerline 40, but is isolated from at least one other collision opening. It is shown in the core assembly 70 of this example that the collision opening and the collision structural member 46 are arranged around the center line 40, but other configurations and positions of the collision opening are intended by the present invention. It is within. Those competent in the art will appreciate that the isolation of at least one collision opening with respect to the other collision opening provides the desired advantage of coordinating cooling in the cooling flow path.

With reference to FIG. 10, the core assembly on the side opposite to that shown in FIG. 9 is shown, and the side of the core assembly 70 forming the outer side 56 of the cooling flow path 30 is shown. This aspect of the core assembly 70 illustrates a film structural member 58 that forms the film holes 34 in the completed wing 12. Further, a heat transfer structural member 60 forming a heat transfer ridge 64 in the completed cooling flow path 30 is shown. Further, as shown, the collision structural members 46 are shown by broken lines to indicate the positions of those members with respect to the functional members formed on the outer side surface 56. As can be seen in FIG. 10, the separation structure member 48 and the heat transfer structure member 60 can generate a regulated cooling air flow from the collision opening to the film opening.

Therefore, the core assembly 44 and the blade 12 of the present invention can realize the adjustment and improvement of the cooling air characteristics in the turbine blade assembly 10. In addition, the core assembly 44 comprises a single core capable of forming a plurality of individual channels desirable for separating airflow through each of the collision hole openings. This isolation of the collision opening provides improved airflow and conditioning capabilities that achieve and optimize local cooling and flow characteristics within the wing.

Having disclosed preferred embodiments of the present invention, those with conventional skill in the art will understand that some modifications fall within the scope of the present invention. For this reason, the scope of claims should be examined in order to determine the scope and content of the present invention.

<figref num="1A">It is a side view of the turbine blade assembly according to this invention.</figref><figref num="1B">It is sectional drawing of a part of a turbine blade assembly.</figref><figref num="2">It is a perspective view of a wing assembly.</figref><figref num="3">It is a perspective view of a part of the core assembly according to this invention.</figref><figref num="4">FIG. 3 is a perspective view of a wing assembly according to the present invention, with a portion cut out to illustrate the cooling air flow path.</figref><figref num="5">It is a perspective view of the core assembly according to this invention.</figref><figref num="6">It is a figure of the outer surface of a cooling flow path.</figref><figref num="7">It is a top view of the side surface of the core assembly according to this invention.</figref><figref num="8">It is a top view of the other side surface of the core assembly shown in FIG.</figref><figref num="9">It is a figure of one side of the core assembly according to this invention.</figref><figref num="10">FIG. 9 is a view of the opposite side surface of the core assembly illustrated in FIG.</figref>

Code description

10 ... Turbine blade assembly 12 ... Wing 14 ... Root 16 ... Platform 18 ... Tip 20 ... Front edge 22 ... Trailing edge 24 ... Outer surface 28. .. Main core 30 ... Cooling flow path 32 ... Collision opening 34 ... Film opening 36 ... Channel 38 ... Separation structural member 40 ... Center line 42 ... Expansion chamber 44 ... core assembly 46 ... collision structural members