High order shaped curve region for an airfoil
A turbomachine blade with a localized dihedral feature has a high order polynomial shaped curve region.
1. A turbomachine blade comprising:
an airfoil extending along a spanwise stacking distribution between a root and a tip region, said airfoil including a chordline extending between a leading edge and a trailing edge; and
a dihedral feature of the spanwise stacking distribution, wherein said dihedral feature is generally localized at an end of the spanwise stacking distribution, said dihedral feature being further defined by a curved region of the spanwise stacking distribution of said airfoil, a shape of said curved region being defined by a high order polynomial.
2. The turbomachine blade of claim 1 , wherein said high order polynomial is defined by a polynomial comprising the polynomial term A*(Z−Z blend ) n where, A is a constant, Z is a radial location of the spanwise stacking distribution section, Z blend is a radial location for a blend point of said spanwise stacking distribution, and n is the order of the polynomial.
3. The turbomachine blade of claim 2 , wherein said high order polynomial is defined by Δy′=A*(Z−Z blend ) n .
4. The turbomachine blade of claim 2 , wherein n is greater than or equal to 2.1.
5. The turbomachine blade of claim 2 , wherein n is greater than or equal to 3.
6. The turbomachine blade of claim 1 , wherein said curve region is a region of said airfoil where a spanwise stacking distribution of said airfoil diverges from a radial airfoil stacking line.
7. The turbomachine blade of claim 6 , wherein said airfoil further comprises a blend point where said curve region initially diverges from the radial airfoil stacking line.
8. The turbomachine blade of claim 7 , wherein said blend point is at least at 70% of said span.
9. The turbomachine blade of claim 8 , wherein said blend point is at least at 80% of said span.
10. The turbomachine blade of claim 1 , wherein said dihedral angle is in the range of 15 degrees to 35 degrees.
11. The turbomachine blade of claim 1 , wherein said airfoil is a rotor blade.
12. The turbomachine blade of claim 11 , wherein said airfoil is a rotor blade in a compressor section of a gas turbine engine.
13. The turbomachine blade of claim 1 , wherein said airfoil is a stator blade.
14. The turbomachine blade of claim 13 , wherein said airfoil is a stator blade in a compressor section of a gas turbine engine.
15. The turbomachine blade of claim 1 , wherein said spanwise stacking distribution extends from a root to a tip of said airfoil, and wherein said spanwise stacking distribution is a curve passing through the centroids of each of multiple stacked planar sections of said airfoil.
16. The turbomachine blade of claim 1 , wherein said end of the spanwise stacking distribution is a tip region of said airfoil.
17. The turbomachine blade of claim 1 , wherein said end of the spanwise stacking distribution is a root region of said airfoil.
18. A turbine machine comprising:
a plurality of airfoils wherein each of said airfoils extends along a spanwise stacking distribution between a root and a tip region, said airfoil including a chordline extending from a leading edge and a trailing edge; and
a dihedral feature of the spanwise stacking distribution, wherein said dihedral feature is generally localized at an end of the spanwise stacking distribution, said dihedral feature being further defined by a curved region of the spanwise stacking distribution of said airfoil, a shape of said curved region being defined by a high order polynomial.
19. The turbine machine of claim 18 , wherein said high order polynomial is defined by a polynomial comprising the polynomial term A*(Z−Z blend ) n where, A is a constant, Z is the radial location of the spanwise stacking distribution section, Z blend is a radial location for a blend point of said spanwise stacking distribution, and n is the order of the polynomial.
20. The turbine machine of claim 19 , wherein said high order polynomial is defined by Δy′=A*(Z−Z blend ) n .
21. The turbine machine of claim 20 , wherein n is greater than or equal to 2.1.
22. The turbine machine of claim 20 , wherein n is greater than or equal to 3.
23. The turbine machine of claim 19 , wherein said curve region is a region of said airfoil where a spanwise stacking distribution diverges from a radial airfoil stacking line.
24. The turbine machine of claim 19 , wherein said turbine blade further comprises a blend point where said curve region initially diverges from the radial airfoil stacking line.
25. The turbine machine of claim 19 , wherein said blend point is at least at 70% of said span.
26. The turbine machine of claim 19 , wherein said blend point is at least at 80% of said span.
27. The turbine machine of claim 19 , wherein said dihedral angle is in the range of 15 degrees to 35 degrees.
28. The turbine machine of claim 19 , wherein said turbine machine is a geared turbofan.
29. The turbine machine of claim 19 , wherein said spanwise stacking distribution extends from a root to a tip of said airfoil, and wherein said spanwise stacking distribution is a curve passing through the centroids of each of multiple stacked planar sections of said airfoil.
30. The turbine machine blade of claim 18 , wherein said end of the spanwise stacking distribution is a tip region of said airfoil.
31. The turbine machine blade of claim 18 , wherein said end of the spanwise stacking distribution is a root region of said airfoil.