Patent Publication Number: US-2016245104-A1

Title: Gas turbine engine and turbine configurations

Description:
FIELD 
     The present disclosure relates to gas turbine engines and, in particular, to turbine assemblies and turbine interface configurations for gas turbine engines. 
     BACKGROUND 
     Gas turbine engines are required to operate efficiently during operation and flight. These engines create a tremendous amount of force and generate high levels of heat. As such, components of these engines are subjected to high levels of stress, temperature and pressure. It is necessary to provide components that can withstand the demands of a gas turbine engine. It is also desirable to provide components with increased operating longevity. 
     Some components of a gas turbine engine experience growth due to the high temperature environment of the engine. By way of example, hot section components of an engine may undergo transformations is size during operation. Uneven temperature distributions across engine parts can reduce the fatigue resistance, operation performance and/or operational life of a component. Accordingly, there is a desire to provide configurations that reduce temperature disparities and overcomes one or more of the aforementioned drawbacks. There is also a desire to improve the configuration of gas turbine engines and vane assemblies. 
     BRIEF SUMMARY OF THE EMBODIMENTS 
     Disclosed and claimed herein are gas turbine engines and high pressure turbine vane assemblies for gas turbine engines. One embodiment is directed to a high pressure turbine vane assembly for a gas turbine engine. The vane assembly includes a plurality of turbine vanes, an inner diameter platform coupled to the base portion of each of the plurality of turbine vanes, wherein the leading edge of the inner diameter platform is associated with a first axis, and an outer diameter platform coupled to the top portion of each of the plurality of turbine vanes. The leading edge of the outer diameter platform is associated with a second axis, the second axis offset from the first axis such that the outer platform extends away from the leading edge of the turbine blades a distance greater than an amount the inner platform extends away from the leading edge of the turbine blades. 
     In one embodiment, the plurality of turbine blades are configured for a high lift/low foil count high pressure turbine vane assembly. 
     In one embodiment, a platform length of the outer diameter is greater than 18% of vane pitch. 
     In one embodiment, the plurality of turbine vanes radially extend between the inner diameter platform and outer diameter platform. 
     In one embodiment, the outer diameter platform is a circumferentially extending annular structure wherein leading edges of the inner and outer platforms are configured to define, at least in part, an interface between the vane assembly and a combustor. 
     In one embodiment, the outer diameter platform extends 0.5 inches longer than the inner diameter platform. 
     In one embodiment, the outer diameter platform extends longer than the inner diameter platform with a range of 0.1 inches longer to 1 inch longer. 
     In one embodiment, the outer diameter platform is configured to evenly distribute temperature across the outer diameter platform. 
     In one embodiment, the inner diameter platform and outer diameter platform each extend from the leading edge such that each platform length is at least 18% of vane pitch relative to a respective platform radius. 
     Another embodiment is directed to a gas turbine engine having combustor and turbine interface configuration. The gas turbine engine includes a combustor extending along a portion of a gas turbine engine and a turbine vane assembly configured to interface with the combustor. The turbine vane assembly includes a plurality of turbine vanes, an inner diameter platform coupled to the base portion of each of the plurality of turbine vanes, wherein the leading edge of the inner diameter platform is associated with a first axis, and an outer diameter platform coupled to the top portion of each of the plurality of turbine vanes. The leading edge of the outer diameter platform is associated with a second axis, the second axis offset from the first axis such that the outer platform extends away from the leading edge of the turbine blades a distance greater than an amount the inner platform extends away from the leading edge of the turbine blades. The inner diameter platform and outer diameter platform interface with the combustor. 
     In one embodiment, the plurality of turbine blades are configured for a high lift/low foil count high pressure turbine vane assembly. 
     In one embodiment, a platform length of the outer diameter is greater than 18% of vane pitch. 
     In one embodiment, the plurality of turbine vanes radially extend between the inner diameter platform and outer diameter platform. 
     In one embodiment, the outer diameter platform is a circumferentially extending annular structure wherein leading edges of the inner and outer platforms are configured to define, at least in part, an interface between the vane assembly and a combustor. 
     In one embodiment, the outer diameter platform extends 0.5 inches longer than the inner diameter platform. 
     In one embodiment, the outer diameter platform extends longer than the inner diameter platform with a range of 0.1 inches longer to 1 inch longer. 
     In one embodiment, the outer diameter platform is configured to evenly distribute temperature across the outer diameter platform. 
     In one embodiment, the inner diameter platform and outer diameter platform each extend from the leading edge such that each platform length is at least 18% of vane pitch relative to a respective platform radius. 
     In one embodiment, the inner diameter platform and outer diameter platform are located immediately downstream of the combustor. 
     In one embodiment, an interface between the vane assembly and the combustor includes a gas-path passage between a cavity of the combustor and leading edge of the vanes 
     Other aspects, features, and techniques will be apparent to one skilled in the relevant art in view of the following detailed description of the embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features, objects, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein: 
         FIG. 1  depicts a cross-sectional representation of a gas turbine engine according to one or more embodiments; 
         FIG. 2  depicts a graphical representation of a combustor and vane assembly of a gas turbine engine according to one or more embodiments; and 
         FIGS. 3A-3B  depict a vane assembly according to one or more embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Overview and Terminology 
     One aspect of this disclosure relates to configurations for a gas turbine and in particular combustor and vane interface. According to one embodiment a vane assembly and a configuration for a vane assembly are provided. The vane assembly may be configured to allow for an even temperature distribution base one or more features of the assembly including but not limited to than outer diameter platform of the vane assemble. In one embodiment, a vane assembly includes an outer diameter platform that extends beyond the inner diameter platform of the vane assembly, in a forward direction towards a combustor. As will be discussed herein, the configuration of an outer diameter platform can affect the temperature distribution across the vane assembly to allow for an even temperature distribution. By providing an even temperature distribution, component life and/or operational efficiency may be increased. 
     As used herein, the terms “a” or “an” shall mean one or more than one. The term “plurality” shall mean two or more than two. The term “another” is defined as a second or more. The terms “including” and/or “having” are open ended (e.g., comprising). The term “or” as used herein is to be interpreted as inclusive or meaning any one or any combination. Therefore, “A, B or C” means “any of the following: A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive. 
     Reference throughout this document to “one embodiment,” “certain embodiments,” “an embodiment,” or similar term means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of such phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner on one or more embodiments without limitation. 
     Exemplary Embodiments 
     Referring now to the figures,  FIG. 1  depicts a cross-sectional representation of a gas turbine engine according to one or more embodiments. Gas turbine engine  100  includes combustor  105  and vane assembly  110 . Combustor  105  extends along a portion of a gas turbine engine  100  and provides a gas-flow path from combustor cavity  106  to vane assembly  110 . Vane assembly  110  may be a high pressure turbine vane assembly down stream from combustor  105 . Vane assembly  110  interfaces with combustor  105  such that the interface between the vane assembly  110  and combustor  105  includes a gas-path passage between a cavity  106  of the combustor and leading edge of vanes of vane assembly  110 . 
     According to one embodiment, vane assembly  110  may include a plurality of turbine vanes, such as vane  111 . The leading edge of vane  111  is shown as  115 . Vane assembly  110  includes inner diameter platform  112  coupled to the base portion of each vane of vane assembly  110 . The leading edge  116  of inner diameter platform  112  is associated with a first axis  125 . Outer diameter platform  113  coupled to the top portion of each vane, wherein the leading edge  114  of the outer diameter platform  113  is associated with a second axis  120 . Outer diameter platform  113  is a circumferentially extending annular structure wherein leading edges of the inner and outer platforms  113 ,  112  are configured to define, at least in part, an interface  117  between the vane assembly  110  and combustor  105 . Second axis  120  is offset from first axis  125  such that the outer platform  113  extends away from the leading edge  115  of turbine vane  111 , and the other vanes of vane assembly  110 , a distance  130  greater than an amount the inner platform  112  extends away from the leading edge  115  of turbine  111 . First axis  125  and second axis  120  are reference lines that may be tangential or perpendicular to the axis of rotation of the turbine  111 . 
     Inner diameter platform  112  and outer diameter platform  113  are configured to interface with combustor  105 . According to one embodiment, interface  117  relates to the intersection of cavity region  107  and vane assembly  110 . Outer diameter platform  113  is configured to evenly distribute temperature across the outer diameter platform associated with the interface  117 . According to one embodiment, outer diameter platform  113  extends 0.5 inches longer (i.e., longer in an axial direction towards the front of the engine which translates towards the left side of the image in  FIG. 1 ) than the inner diameter platform  112 . Outer diameter platform  113  extends longer than the inner diameter platform  112  within a range of 0.1 inches longer to 1 inch. Distance  130  may be provided for length of the outer diameter platform  113  that is greater than 18% of vane  111  pitch. According to one embodiment, vane pitch relates to a ratio of circumference to the number airfoils. For outer diameter platform  113 , vane pitch is calculated using the outer diameter of the vane platform at the vane leading edge with respect to a radius of the platform. For inner diameter platform  112 , vane pitch is calculated using the inner diameter of the vane platform at the vane leading edge with respect to a radius of the platform. 
       FIG. 2  depicts a graphical representation of a combustor and vane assembly of a gas turbine engine according to one or more embodiments. Combustor  200  is shown as an annular combustor having outer diameter portion  205  and inner diameter portion  206 . Combustor  200  interfaces with vane assembly  210  include a plurality of vanes, such as vane  215 . According to one embodiment, vane assembly  210  is the first stage of a high pressure turbine. Vane  215  includes leading edge  216  and trailing edge  217 . Vane  215  is fit between outer diameter platform  220  and inner diameter platform  225 . 
     An interface between combustor  200  interfaces with vane assembly  210  is shown as  230 . According to one embodiment, interface  230  is configured to allow for outer diameter platform  220  to extend further than inner diameter platform  225  towards combustor  200 . As such, the temperature distribution in the interface may be evenly distributed. 
       FIGS. 3A-3B  depict a vane assembly according to one or more embodiments.  FIG. 3A  depicts a view of vane assembly  300  according to one or more embodiments. According to one embodiment, vane assembly  300  includes one or more vanes, such as vane  305 , an inner diameter platform  315  and outer diameter platform  310 . Vane assembly  300  may be a high pressure turbine vane assembly. According to another embodiment, a plurality of turbine vanes of vane assembly  300  are configured for a high lift/low foil count turbine vane assembly. As used herein, a high lift/low foil count turbine vane assembly can relate to a vane assembly of a high pressure turbine assembly aft of the combustor. The plurality of turbine vanes radially extend between the inner diameter platform  315  and outer diameter platform  310 . 
       FIG. 3B  depicts a partial representation, shown as  320 , of vane assembly  300  for two vanes of the assembly. Vane  305  is shown including leading edge  321  and trailing edge  322 . According to one embodiment, diameter platform  310  extends beyond the leading edge of vane  305  as shown by  325 . Region  325  relates to a combustor vane assembly interface region. 
     While this disclosure has been particularly shown and described with references to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the claimed embodiments.