Optimized aerodynamic profile for a turbine blade, in particular for a rotary wheel of the fourth stage of a turbine
When cold and in the non-coated state, the aerodynamic profile is substantially identical to a nominal profile determined by the Cartesian coordinates X,Y,Z′ given in Table 1, in which the coordinate Z′ is the quotient D/H where D is the distance of the point under consideration from a first reference plane P 0 situated at the base of the nominal profile, and H is the height of said profile measured from the first reference plane to a second reference plane P 1 . The measurements D and H are taken radially relative to the axis of the turbine, while the X coordinate is measured in the axial direction of the turbine.
1. An aerodynamic profile for a turbine blade, the profile being, when cold and in a non-coated state, substantially identical to a nominal profile determined by the Cartesian coordinates X,Y,Z′ given in Table 1, in which the coordinate Z′ is the quotient D/H, where D is the distance of the point under consideration from a first reference X,Y plane situated at the base of the nominal profile, and H is the height of said profile measured from said first reference plane that is the intersection of the stacking axis of the set of blades and the axisymmetric surface of the hub, out to a second reference plane that is the intersection of said stacking axis with the axisymmetric surface of the casing, the measurements D and H being taken radially relative to the axis of the turbine, while the coordinate X is measured in the axial direction of the turbine.
2. The aerodynamic profile as claimed in claim 1 , wherein said profile is defined within an envelope of ±1 mm in a direction normal to the surface of the nominal profile.
3. The aerodynamic profile as claimed in claim 1 , wherein the coordinates X,Y of said profile lie within a range of ±5% relative to the coordinates X,Y of the nominal profile.
4. The aerodynamic profile as claimed in claim 1 , wherein the blade is a blade of a rotary wheel forming a portion of a rotor of a turbine.
5. The aerodynamic profile as claimed in claim 4 , wherein the blade is a blade of the rotary wheel of the fourth stage of the turbine.
6. The aerodynamic profile as claimed in claim 4 , wherein the blade is a blade of the rotary wheel of the fourth stage of a turbine having four stages.
7. A turbine blade, presenting an aerodynamic profile as claimed in claim 1 .
8. A turbine, including turbine blades presenting aerodynamic profiles as claimed in claim 1 .
9. A turbine as claimed in claim 8 , including a rotary wheel, having 120 to 140 blades.
10. A rotary wheel of a turbine forming a portion of a turbine rotor, wherein all the blades of this rotary wheel present an aerodynamic profile as claimed in claim 1 .
11. The rotary wheel of a turbine as claimed in claim 10 , including 120 to 140 blades.