The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a turbomachine component having an airfoil core shape.
Many system requirements must be met for each stage of a turbomachine in order to meet design goals including an overall improvement in system efficiency. In particular, third stage nozzles must meet system requirements including airfoil loading and manufacturability. These third stage nozzles must operate within a particular set of boundary conditions based on operating conditions of the turbomachine while maintaining a shape that meets design specifications.
According to one aspect of the exemplary embodiment, a turbomachine component includes a turbine stator nozzle member having an airfoil core shape. The airfoil core shape includes a nominal profile substantially in accordance with Cartesian coordinate values of X, Y, and Z set forth in TABLE 1, and wherein X and Y are distances in inches which, when connected by smooth continuing arcs, define airfoil profile sections at each distance Z in inches, the profile sections at the Z distances being joined smoothly with one another to form a complete airfoil core shape.
According to another aspect of the exemplary embodiment, a turbomachine includes a turbine portion, and a turbine stator nozzle member provided in the turbine portion. The turbine stator nozzle member includes an airfoil core shape. The airfoil core shape includes a nominal profile substantially in accordance with Cartesian coordinate values of X, Y, and Z set forth in TABLE 1, and wherein X and Y are distances in inches which, when connected by smooth continuing arcs, define airfoil profile sections at each distance Z in inches, the profile sections at the Z distances being joined smoothly with one another to form a complete airfoil core shape.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
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Airfoil core shape 44 in accordance with an exemplary embodiment is configured for enhanced turbine performance. A list of X, Y, and Z coordinates or points for airfoil core shape 44 is presented in TABLE 1, and meets requirements for interaction between adjacent stages, aerodynamic efficiency and provides an improved aeromechanics margin over prior shapes. Moreover, the particular airfoil core shape 44 in accordance with the exemplary embodiment meets system requirements for flow dynamics, loading, and frequency response. The points are arrived at by iteration between aerodynamic and mechanical design improvements and are the only loci of points that allow turbomachine 2 to operate in an efficient, smooth manner. As will become more fully evident below, airfoil core shape 44 is represented as a set of 1920 points listed in TABLE 1. The 1920 points represent 15 airfoil sections. The X, Y, and Z coordinates, which represent a profile of airfoil core shape 44, are created in a coordinate system which is defined relative to a cold engine part. The origin of the coordinate system on the cold centerline axis is X=0.0, Y=0.0 and Z=0.0. The Z coordinate axis is defined as a radial line from the Y coordinate axis; the X coordinate axis is defined as being normal to a plane defined by the Y-Z axis. The airfoil sections are cut normal to the Z coordinate axis. X and Y points, which make up the airfoil core profile shape 44 at each section, are in inches. The radial Z values in inches for the section planes have an origin of Z0.
The radial distance between each section varies however a total radial distance of airfoil core shape 44 is 15.0 inches. The bottom and top sections Z0 and Z1, may be obscured by cast-in features that are not included in the X, Y, and Z points that define airfoil core shape 44. All of the 1920 points are taken from a nominal cold or room temperature for each airfoil section of airfoil core shape 44. Each airfoil section is joined smoothly with adjacent airfoil sections to form the airfoil core shape 44.
It should be appreciated that as nozzle assembly 20 heats up during operation of turbine portion 4, airfoil core shape 44 may change as a result of stress and temperature. Thus, the X, Y and Z points are provided at cold or room temperature for manufacturing purposes. Since the manufactured airfoil core shape may be different from a nominal airfoil core shape defined in Table 1, a tolerance of ±0.100 inches from the nominal profile is allowed and thus defines an overall design envelope for airfoil core shape 44. The overall design is robust to this design envelope without impairment of mechanical or aerodynamic properties of third turbine stage 34.
It should also be appreciated that the airfoil core shape 44 can be scaled up or scaled down geometrically for introductions into similar turbine designs, with smaller or larger frame sizes. Consequently, the X, Y, and Z coordinates in inches may be multiplied or divided by the same constant or number/factor to provide a scaled up or scaled down version of third stage nozzle 40 while retaining the airfoil core profile shape and unique properties.
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In no way limiting of the exemplary embodiment, airfoil core shape 44 provides an increased efficiency as compared to previous individual airfoil core shapes for third stage nozzle member 40. Moreover, and in no way limiting of the exemplary embodiment, in conjunction with other airfoil core shapes, which are conventional or enhanced (similar to the enhancements herein), airfoil core shape 44, as embodied by the invention, provides an increased efficiency as compared to previous individual sets of airfoil core shapes for third stage nozzle member 40. This increased efficiency provides, in addition to the above-noted advantages, a power output with a decrease the required fuel, therefore inherently decreasing emissions to produce energy. Of course, other such advantages are within the scope of the exemplary embodiment.
At this point it should be understood that the points disclosed in Table 1 are exemplary, variations/deviations from the points in Table 1 at one or more sections that do not substantially affect the desired properties obtained by the airfoil core shape of the exemplary embodiments fall within the scope of the exemplary embodiments of the invention.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.