Turbine nozzle airfoil profile

The present application provides a turbine nozzle including an airfoil shape. The airfoil shape may have a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in Table 1. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances in inches by multiplying the Cartesian coordinate values of X, Y and Z by a height of the airfoil in inches. The X and Y values are distances in inches which, when connected by smooth continuing arcs, define airfoil profile sections at each distance Z. The airfoil profile sections at Z distances may be joined smoothly with one another to form a complete airfoil shape.

TECHNICAL FIELD

The present application and the resultant patent relate generally to a turbine nozzle for a turbine engine and more particularly relate to a nozzle airfoil profile for a turbine stage.

BACKGROUND OF THE INVENTION

In a turbine, many system requirements should be met at each stage of the turbine so as to meet design goals. These turbine design goals may include, but are not limited to, overall improved efficiency and airfoil loading capability. For example, a turbine nozzle airfoil profile should achieve thermal and mechanical operating requirements for that particular stage. Moreover, component lifetime and cost targets also should be met.

There is thus a desire therefore for an improved turbine nozzle airfoil profile for use in a turbine and the like. Such an improved airfoil design should achieve performance objectives and improve overall gas turbine performance in a component with a long lifetime and reasonable manufacture and operating costs.

SUMMARY OF THE INVENTION

The present application and the resultant patent thus provide a turbine nozzle including an airfoil shape. The airfoil shape may have a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in Table 1. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances in inches by multiplying the Cartesian coordinate values of X, Y and Z by a height of the airfoil in inches. The X and Y values are distances in inches which, when connected by smooth continuing arcs, define airfoil profile sections at each distance Z. The airfoil profile sections at Z distances being joined smoothly with one another to form a complete airfoil shape.

The present application and the resultant patent further provide a turbine nozzle including an airfoil having a suction-side uncoated nominal airfoil profile substantially in accordance with suction-side Cartesian coordinate values of X, Y and Z set forth in Table 1. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances in inches by multiplying the Cartesian coordinate values of X, Y and Z by a height of the airfoil in inches. The X and Y values are distances in inches which, when connected by smooth continuing arcs, define airfoil profile sections at each Z distance. The airfoil profile sections at the Z distances may be joined smoothly with one another to form a complete suction-side airfoil shape. The X, Y and Z distances being scalable as a function of the same constant or number to provide a scaled-up or scaled-down airfoil.

The present application and the resultant patent further provide a turbine with a number of nozzles having an airfoil having an airfoil shape. The airfoils having a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in Table 1. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances in inches by multiplying the Cartesian coordinate values of X, Y and Z by a height of the airfoil in inches. The X and Y values are distances in inches which, when connected by smooth continuing arcs, define airfoil profile sections at each Z distance. The airfoil profile sections at the Z distances may be joined smoothly with one another to form a complete airfoil shape.

DETAILED DESCRIPTION

Referring now to the drawings, in which like numerals refer to like elements throughout the several views,FIG. 1shows a schematic view of gas turbine engine10as may be used herein. The gas turbine engine10may include a compressor15. The compressor15compresses an incoming flow of air20. The compressor15delivers the compressed flow of air20to a combustor25. The combustor25mixes the compressed flow of air20with a pressurized flow of fuel30and ignites the mixture to create a flow of combustion gases35. Although only a single combustor25is shown, the gas turbine engine10may include any number of combustors25. The flow of combustion gases35is in turn delivered to a turbine40. The flow of combustion gases35drives the turbine40so as to produce mechanical work. The mechanical work produced in the turbine40drives the compressor15via a shaft45and an external load50such as an electrical generator and the like.

The gas turbine engine10may use natural gas, various types of syngas, and/or other types of fuels. The gas turbine engine10may be any one of a number of different gas turbine engines offered by General Electric Company of Schenectady, N.Y., including, but not limited to, those such as a 7 or a 9 series heavy duty gas turbine engine and the like. The gas turbine engine10may have different configurations and may use other types of components. Other types of gas turbine engines also may be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation equipment also may be used herein together.

FIG. 2shows a schematic diagram of a turbine100as may be described herein. The turbine100may include a first stage110, a second stage120, a third stage130, a fourth stage140, a fifth stage142, a sixth stage144, and the like. Any number of stages may be used herein. For example, the first stage110may include a number of circumferentially spaced nozzles150and buckets160. The first stage buckets160are mounted on a turbine rotor170. The nozzles150are circumferentially spaced one from the other and fixed about an axis of the rotor. The second stage of the turbine100includes a number of circumferentially spaced nozzles180and a number of circumferentially spaced buckets190mounted on the rotor170. The third stage also includes a number of circumferentially spaced nozzles200and buckets210mounted on the rotor170. The fourth stage140includes a number of circumferentially spaced nozzles220and buckets230mounted on the rotor170. The fifth stage142includes a number of circumferentially spaced nozzles232and buckets234mounted on the rotor170. The sixth stage144includes a number of circumferentially spaced nozzles236and buckets238mounted on the rotor170. Again, any number of stages may be used herein. It will be appreciated that the nozzles and buckets lie in a hot gas path240of the turbine. Other components and other configurations may be used herein.

Referring toFIGS. 3 and 4, it will be appreciated that each nozzle180has a nozzle airfoil250as illustrated. The airfoil250may have a suction side260and a pressure side270. The suction side260is shown inFIG. 4and the pressure side270is located on the opposing side of the airfoil250. Thus, each of the nozzles180has a nozzle airfoil profile at any cross-section in the shape of the airfoil250. A tip280is at or near the top of the airfoil250and a base290is at or near the bottom of the airfoil250. The airfoil250also includes a leading edge300, a trailing edge310, and a chord length320therebetween. The base290corresponds to the non-dimensional Z value of Table 1 at Z equals 0. The tip280of the nozzle airfoil250corresponds to the non-dimensional Z value of Table 1 at Z equals 100. The X, Y, and Z values are given in percentage values of the airfoil length. As one example only, the height of the turbine nozzle or airfoil250may be from about 5 inches to about 50 inches (about 12 centimeters to about 130 centimeters). However, it is to be understood that heights below or above this range may also be employed as desired in the specific application. The airfoil250may be used for any stage, including but not limited to a first stage, a second stage, a third stage, a fourth stage, a fifth stage, and the like.

The gas turbine hot gas path240requires airfoils250that meet system requirements of aerodynamic and mechanical blade loading and efficiency. To define the airfoil shape of each nozzle airfoil, there is a unique set or loci of points in space that meet the stage requirements and can be manufactured. These unique loci of points meet the requirements for stage efficiency and are arrived at by iteration between aerodynamic and mechanical loadings enabling the turbine to run in an efficient, safe and smooth manner. These points are unique and specific to the system. The locus that defines the nozzle airfoil profile includes a set of about 2,200 points with X, Y and Z dimensions relative to a reference origin coordinate system. The Cartesian coordinate system of X, Y and Z values given in Table 1 below defines the profile of the nozzle airfoil at various locations along its length. Table 1 lists data for a non-coated airfoil. The envelope/tolerance for the coordinates is about +/−5% in a direction normal to any airfoil surface location and/or about +/−5% of the chord length320in a direction nominal to any airfoil surface location. The point data origin is the leading edge of the base290. The coordinate values for the X. Y and Z coordinates are set forth in non-dimensionalized units by the blade height in Table 1 although other units of dimensions may be used when the values are appropriately converted. The X, Y, and Z values set forth in Table 1 are also expressed in non-dimensional form (X, Y, and Z) from 0% to 100% of the blade or airfoil height. As one example only, the Cartesian coordinate values of X, Y and Z may be convertible to dimensional distances by multiplying the X, Y and Z values by a height of the airfoil at the trailing edge and multiplying by a constant number (e.g., 100). To convert the Z value to a Z coordinate value, e.g., in inches, the non-dimensional Z value given in Table 1 is multiplied by the Z length of the airfoil in inches. As described above, the Cartesian coordinate system has orthogonally-related X, Y and Z axes and the X axis lies generally parallel to the turbine rotor centerline, i.e., the rotary axis and a positive X coordinate value is axial toward the aft, i.e., exhaust end of the turbine. The positive Y coordinate value extends tangentially in the direction of rotation of the rotor and the positive Z coordinate value is radially outwardly toward the nozzle tip. All the values in Table 1 are given at room temperature and are unfilleted.

By defining X and Y coordinate values at selected locations in a Z direction normal to the X, Y plane, the profile section or airfoil shape of the nozzle airfoil, at each Z distance along the length of the airfoil can be ascertained. By connecting the X and Y values with smooth continuing arcs, each profile section at each distance Z is fixed. The airfoil profiles of the various surface locations between the distances Z are determined by smoothly connecting the adjacent profile sections to one another to form the airfoil profile.

The Table 1 values are generated and shown to four decimal places for determining the profile of the airfoil. As the blade heats up in surface, stress and temperature will cause a change in the X, Y and Z values. Accordingly, the values for the profile given in Table I represent ambient, non-operating or non-hot conditions (e.g., room temperature) and are for an uncoated airfoil.

There are typical manufacturing tolerances as well as coatings which must be accounted for in the actual profile of the airfoil. Each section is joined smoothly with the other sections to form the complete airfoil shape. It will therefore be appreciated that +/− typical manufacturing tolerances, i.e., +/− values, including any coating thicknesses, are additive to the X and Y values given in Table 1 below. Accordingly, a distance of +/−5% in a direction normal to any surface location along the airfoil profile defines an airfoil profile envelope for this particular nozzle airfoil design and turbine, i.e., a range of variation between measured points on the actual airfoil surface at nominal cold or room temperature and the ideal position of those points as given in the Table below at the same temperature. The data is scalable and the geometry pertains to all aerodynamic scales, at above and/or below 3000 RPM. The nozzle airfoil design is robust to this range of variation without impairment of mechanical and aerodynamic functions.

It will also be appreciated that the airfoil250disclosed in the above Table 1 may be scaled up or down geometrically for use in other similar turbine designs. Consequently, the coordinate values set forth in Table 1 may be scaled upwardly or downwardly such that the airfoil profile shape remains unchanged. A scaled version of the coordinates in Table 1 would be represented by X, Y and Z coordinate values of Table 1, with the X, Y and Z non-dimensional coordinate values converted to inches, multiplied or divided by a constant number.

An important term in this disclosure is profile. The profile is the range of the variation between measured points on an airfoil surface and the ideal position listed in Table 1. The actual profile on a manufactured blade will be different than those in Table 1 and the design is robust to this variation meaning that mechanical and aerodynamic function are not impaired. As noted above, a + or −5% profile tolerance is used herein. The X, Y and Z values are all non-dimensionalized relative to the airfoil height.

The disclosed airfoil shape optimizes and is specific to the machine conditions and specifications. The airfoil shape provides a unique profile to achieve (1) interaction between other stages in the high pressure turbine; (2) aerodynamic efficiency; and (3) normalized aerodynamic and mechanical blade loadings. The disclosed loci of points allow the gas turbine or any other suitable turbine to run in an efficient, safe and smooth manner. As also noted, any scale of the disclosed airfoil may be adopted as long as (1) interaction between other stages in the high pressure turbine; (2) aerodynamic efficiency; and (3) normalized aerodynamic and mechanical blade loadings are maintained in the scaled turbine.

The airfoil250described herein thus improves overall gas turbine100efficiency. Specifically, the airfoil250provides the desired turbine efficiency lapse rate (ISO, hot, cold, part load, etc.). The airfoil250also meets all aeromechanics and stress requirements.