Cooling arrangement for turbine components

A turbine component includes an aft cooling circuit that extends between a turbine midsection and a turbine trailing end. The aft cooling circuit includes a trailing end section proximate the trailing end, a first interior section proximate the turbine midsection, and a first intermediate section fluidly connected between the trailing end section and the first interior section. A forward cooling circuit of the turbine component extends between the turbine midsection and a turbine leading end. The forward cooling circuit includes a leading end section proximate the leading end, a second interior section proximate the turbine midsection, and a plurality of second intermediate sections fluidly connected between the leading end section and the second interior section. The leading end section, the second intermediate section, the first intermediate section, and the trailing end section each include a plurality of coolant discharge openings for facilitating cooling of the turbine component.

BACKGROUND OF THE INVENTION

This disclosure relates to an arrangement of coolant discharge openings of a turbine component used in a gas turbine engine.

Gas turbine engines are commonly used for propelling an aircraft, for example. A conventional gas turbine engine includes a compressor section, a combustion section, and a turbine section having turbine blades and turbine vanes. The compressor section compresses air, which is mixed with fuel and burned in the combustion section to produce a hot gas stream that expands in the turbine section. Thus, the turbine blades and vanes operate within a relatively hot environment.

SUMMARY OF THE INVENTION

The disclosed example turbine components and gas turbine engine include a cooling arrangement that facilitates cooling of the turbine components.

An example turbine component includes an aft cooling circuit that extends between a turbine midsection and a turbine trailing end. The aft cooling circuit includes a trailing end section proximate the trailing end, a first interior section proximate the turbine midsection, and a first intermediate section fluidly connected between the trailing end section and the first interior section. A forward cooling circuit extends between the turbine midsection and a turbine leading end. The forward cooling circuit includes a leading end section proximate the leading end, a second interior section proximate the turbine midsection, and a plurality of second intermediate sections fluidly connected between the leading end section and the second interior section. The leading end section, the second intermediate section, the first intermediate section, and the trailing end section each include a plurality of coolant discharge openings for facilitating cooling of the turbine component.

In a further example, the turbine component includes coolant discharge openings only in the leading end section, one of the plurality of second intermediate sections, the first intermediate section, and the trailing end section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1illustrates selected portions of an example gas turbine engine10, such as a gas turbine engine10used for propulsion. In this example, the gas turbine engine10is circumferentially disposed about an engine centerline12. The engine10in this example includes a fan14, a compressor section16, a combustion section18, and a turbine section20that includes turbine blades22and turbine vanes24. As is known, air compressed in the compressor section16is mixed with fuel that is burned in the combustion section18to produce hot gasses that are expanded in the turbine section20to drive the fan14.FIG. 1is a schematic presentation for illustrative purposes only and is not a limitation on the disclosed examples. Additionally, there are various types of gas turbine engines, many of which could benefit from the examples disclosed herein.

FIGS. 2 and 3illustrate examples of one of the turbine blades22shown inFIG. 1. Although the description below is made with reference to the turbine blade22, it is to be understood that the examples may also be applied to other airfoil shaped components that may require cooling, such as the turbine vanes24.

The turbine blade22includes an airfoil section34that extends between a tip36and a base38. The airfoil section34is secured to a platform section40at the base38. The airfoil section34includes a leading end42(e.g., edge) that is generally oriented forward in the gas turbine engine10relative to flow through the gas turbine engine10, and a trailing end44(e.g., edge) that is oriented downstream from the leading end42. The airfoil shape of the airfoil section34also includes a pressure side46and a suction side48that refer to relative pressures created when the hot gas stream from the combustion section18flows over the airfoil shape of the airfoil section34.

The turbine blade22also includes an aft cooling passage58(i.e., circuit) and a forward cooling passage60(i.e., circuit) for facilitating cooling of the turbine blade22. The cooling passages58and60are fluidly connected with the compressor section16to receive a bleed flow62(FIG. 1) of relatively cool air that functions as a coolant to internally cool the turbine blade22and provide film cooling over the outer surfaces of the turbine blade22, as will be described below.

FIG. 4illustrates a core72used to form the turbine blade22. That is, the turbine blade22is formed around the core72, such as by using a casting technique. Subsequently, the core72is removed (e.g., by leaching), leaving the cooling passages58and60within the turbine blade22. Thus, the core72represents a solid form of the passages58and60and is used herein to illustrate the shape of the passages58and60(e.g., a serpentine shape).

The aft cooling passage58includes a trailing end section74that is located near the trailing end44of the turbine blade22, a first interior section76that is located near a midsection78(e.g., a mid-chord location between the leading end42and the trailing end44) of the turbine blade22, and a first intermediate section80between the trailing end section74and the first interior section76. The first interior section76functions as an inlet for receiving the bleed flow62, as represented by arrow82. The first interior section76extends lengthwise between the base38to the tip36of the turbine blade22and transitions into the first interior section76through turn section84a. The first intermediate section80extends lengthwise between the base38to the tip36from the turn section84ato another turn section84b, which provides a transition from the first intermediate section80into the trailing end section74.

The forward cooling passage60also includes several sections. A leading end section86is located near the leading end42of the turbine blade22, a second interior section88is located near the midsection78of the turbine blade22, and a plurality of second intermediate sections90are located between the leading end section86and the second interior section88. In the disclosed example, there are two of the second intermediate sections90. However, in other examples, there may be additional second intermediate sections90or only one intermediate section90, depending upon the design of the turbine blade22.

The second interior section88functions as an inlet for receiving the bleed flow62, as represented by the arrow92. The second interior section88generally extends lengthwise between the base38to the tip36of the turbine blade22and transitions into the plurality of second intermediate sections90through a turn section94a. The plurality of second intermediate sections90also include another turn section94b. The forward one of the second intermediate sections90that is located near the leading end42of the turbine blade22is also connected with the leading end section86through a series of openings95(FIG. 3) along the length of the leading end section86.

The turbine blade22includes an arrangement of coolant discharge openings96(FIG. 2), e.g. film cooling holes, that discharge the bleed flow62from the sections74,76,80,86,88, or90such that the bleed flow62forms a film of relatively cool air over portions of the outer surface of the turbine blade22that protect the turbine blade22from the elevated temperatures of the hot gas stream from the combustion section18. For example, at least a portion of the coolant discharge openings96include a constant area portion97aand a tapered portion97bthat opens to the surface of the turbine blade22. The tapered portion97bfacilitates discharging the bleed flow62over a greater surface area of the turbine blade22, as well as producing a film of the bleed flow62over the surface rather than jetting the bleed flow62into the passing hot gas stream.

The particular arrangement of the coolant discharge openings96facilitates effective cooling of the outer surface of the turbine blade22. For example, the temperature at different locations of the turbine blade22depends to a significant extent on the design of the blade22. That is, the shape of the airfoil determines how the hot gas stream flows over the airfoil and thereby influences the temperature experienced at different locations. The number and size of internal cooling passages also influences the temperature. Thus, an arrangement of cooling discharge openings for one blade may not necessarily be applicable to blades having a different shape and different cooling passage design. The location of the various coolant discharge openings96of the turbine blade22will now be described with reference to the sections74,76,80,86,88, and90.

The leading end section88includes four sets of the coolant discharge openings96, including coolant discharge opening sets96a,96b,96c, and96d(hereafter96a-d). The sets96a-dare arranged in a “shower head” formation. That is, the sets96a-ddischarge the bleed flow62in a variety of different directions relative to the pressure side46and the suction side48. In the illustrated example, set96adischarges to the suction side48, and set96ddischarges to the pressure side46. Sets96band96calso discharge to the suction side48. As can be appreciated fromFIG. 2, each set96a-dextends in a row between the tip36and the base38. Thus, the sets96a-dprovide cooling along the leading end42of the turbine blade22.

The forward one of the plurality of second intermediate sections90also includes a set96eof the coolant discharge openings96. The set96eextends in a row between the tip36and the base38. Likewise, the first intermediate section80of the aft cooling passage58also includes a set96fof the coolant discharge openings96that extends in a row between the tip36and the base38. The trailing end section74includes another set96gof the coolant discharge openings96that discharge bleed flow62through the trailing end44of the turbine blade22. The trailing end section74also includes pedestals98to provide turbulent flow through the coolant discharge openings96of set96g. Likewise, the sections74,76,80,86,88, and90may include trip strips99to mix the bleed flow62and facilitate uniform cooling of the turbine blade22.

The illustrated arrangement of the sets96a-gof the cooling discharge openings96facilitates cooling for the particular design of the turbine blade22, which tends to experience a hot zone100on the pressure side46that extends span-wise between set96dand set96f. The temperature of a particular location on a turbine blade or the location of a hot zone may be predicted using a computer simulation or estimated after a period of service in an engine, for example. In this regard, sets96d-fof the coolant discharge openings96provide a film of the bleed flow62over the surface of the pressure side46to cool the pressure side46, including the hot zone100. Set96ddischarges a film of the bleed flow62over the portion of the surface of the pressure side46between set96dand set96e. Set96edischarges a film of the bleed flow62over the portion of the surface of the pressure side46between set96eand set96f, and set96fdischarges a film of the bleed flow62over the portion of the surface of the pressure side46between set96fand the trailing end44. Thus, sets96d-fcool a substantial portion of the surface of the pressure side46, including the hot zone100corresponding to the airfoil shape of the turbine blade22.