Airfoil core shape for a turbomachine component

A turbomachine component includes a compressor stator vane 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 are joined smoothly with one another to form a complete airfoil core shape.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to an airfoil shape of a turbomachine component.

Many system requirements must be met for each stage of a gas turbine in order to meet design goals including an overall improvement in compressor efficiency. In particular, first stage compressor stator vanes must meet system requirements including airfoil loading and manufacturability. These first stage compressor stator vanes must operate within a particular set of boundary conditions based on operating conditions of the gas turbine while maintaining a shape that meets design specifications.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the exemplary embodiment, a turbomachine component includes a compressor stator vane 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 are joined smoothly with one another to form a complete airfoil core shape.

According to another aspect of the exemplary embodiment, a turbomachine includes a compressor portion, and at least one compressor vane provided in the compressor portion. The compressor stator vane 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 are joined smoothly with one another to form a complete airfoil core shape.

DETAILED DESCRIPTION OF THE INVENTION

As shown inFIGS. 1-4, a turbomachine2constructed in accordance with an exemplary embodiment includes a compressor portion4and a turbine portion (not shown). Compressor portion4is enclosed by a compressor housing6and has an axial flow path8. Compressor portion4includes a plurality of variable and stationary vanes, and moving rotor blades two of which are shown at18and20respectively. Compressor portion4is also shown to include additional compressor stages (not separately labeled) the number of which can vary depending upon compressor make and model. Among the stationary vanes18is stator “0” or a first stage compressor stator vane22for 7F, 7FA, 7FA+, 7FA+e gas turbine frames.

In the exemplary embodiment shown, first stage compressor stator vane22includes an airfoil core shape30having first and second ends34and36. First end34is provided with a base member38that serves as an anchor point. More specifically, base member38is a dovetail portion that interfaces with a second dovetail slot (not shown) to locate it in the compressor flow path. Airfoil core shape30has a profile including a three dimensional (3-D) shape that defines a suction side44and a pressure side46as well as a leading edge49and a trailing edge48.

An important aspect of first stage compressor stator vane22is airfoil core shape30, which 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 shape30is presented in TABLE I, and meets compressor requirements for interaction between adjacent stages, aerodynamic efficiency and provides an improved aeromechanics margin over prior shapes. Moreover, the particular airfoil core shape30in 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 turbomachine2to operate in an efficient, smooth manner. As will become more fully evident below, airfoil core shape30is represented as a set of 3024 points listed in TABLE 1. The 3024 points represent 27 airfoil sections each containing 112 points, of which 24 sections comprise airfoil core shape30. The X, Y, and Z coordinates, which represent a profile of airfoil core shape30, 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 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 shape30is 15.4294 inches. The bottom and top sections Z0and Z1, may be obscured by cast-in features, such as base member38, that are not included in the X, Y, and Z points that define airfoil core shape30. All of the 3024 points are taken from a nominal cold or room temperature for each airfoil section of airfoil core shape30. Each airfoil section is joined smoothly with adjacent airfoil sections to form the airfoil core shape30.

It should be appreciated that as each compressor stator vane22heats up during operation of compressor portion4, the airfoil core profile shape will 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 +0.160 and −0.0 inches from the nominal profile is allowed and thus defines an overall design envelope for airfoil core shape30. The overall design is robust to this design envelope without impairment of mechanical or aerodynamic properties of first stage compressor stator vane22.

It should also be appreciated that the airfoil core shape30can 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 first stage stator vane22while retaining the airfoil core profile shape and unique properties.

As best shown inFIG. 2, a coordinate system for airfoil core shape30in accordance with exemplary embodiment is indicated generally at100. As discussed above, coordinate system100is defined relative to a cold stator vane. Coordinate system100includes an X-axis105, a Y-axis110, and a Z-axis115. The origin of coordinate system100is centered on a point located on first stage compressor stator vane22covered by base member38. X-axis105is directed axially along a centerline axis (not separately labeled) of turbomachine2and Z-axis115is directed along a radial line normal to the centerline axis. The positive direction of X-axis105, Y-axis110, and Z-axis115is identified by label placement inFIG. 2.

As best shown inFIGS. 3 and 4, airfoil core shape30includes a plurality of sections150-172. Section150is located at Z0and the airfoil core shape30extends through sections172before terminating at section180located at Z1. As discussed above, sections150-172, and180are cut normal to ZC-axis115. The X and Y coordinates which make up each section are presented in Table 1 are in inches.FIG. 5illustrates a set of 112 points200which make up section151.

FIG. 6illustrates a design envelope for airfoil core shape30. The X, Y, and Z values listed in TABLE 1 illustrate ideal point location for each point of each section of airfoil core shape30. However, there exist variations from the ideal point location attributed to manufacturing tolerances and the like which must be taken into account. Thus, a design envelope is established which sets forth an acceptable outer boundary or distance from a nominal profile250for each section150-172, and180. Therefore it should be understood that each X, Y, and Z point includes a tolerance or ±value. In consideration of process capability, a tolerance260of +0.160 inches is allowed in the formation of airfoil core shape30. Tolerance260includes an upper limit270defined as a 0.160-inch deviation from nominal profile250and a lower limit280, defined as a −0.000-inch variation from nominal profile250. The design envelope or tolerance260is robust such that this variation does not impair mechanical and aerodynamic performance of compressor stator vane22.

In no way limiting of the exemplary embodiment, airfoil core shape30provides an increased efficiency as much as 0.15% compared to previous individual airfoil core shapes for first stage compressor stator vane22. 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 shape30, as embodied by the invention, provides an increased efficiency as much as 0.15% compared to previous individual sets of airfoil core shapes for first stage compressor stator vane22. 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.