Vane with L-shaped seal

1. A vane comprising:

a ceramic vane piece defining first and second vane platforms and a hollow airfoil section joining the first and second vane platforms;

a structural platform adjacent the first platform, the structural platform defining a radial seal slot; and

a seal having a radial leg and an axial leg, the seal including a filet that joins the radial leg and the axial leg such that the seal has an L-shaped cross-section, the radial leg extending in the radial seal slot and the axial leg extending in an interface between the structural platform and the first vane platform, the radial leg extending from the filet to a tip edge, the tip edge having a concavity, and the structural platform defining a purge hole that opens at the radial seal slot and exits over the concavity.

2. The vane as recited in claim 1 , further comprising a pressure tap that opens to the seal.

3. The vane as recited in claim 1 , wherein the axial leg defines an axial length, the radial leg defines a radial length, and the axial length is greater than the radial length.

4. The vane as recited in claim 1 , wherein the radial leg and the axial leg are arced.

5. The vane as recited in claim 1 , wherein the seal is formed of a metallic material and has a thickness of 0.15 millimeters to 0.28 millimeters.

6. The vane as recited in claim 1 , wherein the structural platform further comprises an axial seal slot extending from the radial seal slot.

7. The vane as recited in claim 1 , wherein the radial leg and the axial leg form an angle of 60° to 105°.

8. A vane comprising:

a ceramic vane piece defining first and second vane platforms and a hollow airfoil section joining the first and second vane platforms, the first vane platform having a radially outer face defining a bearing surface;

a structural platform adjacent the radially outer face, the structural platform defining a radial seal slot, an expansion gap along an interface between the first vane platform and the structural platform, the expansion gap varying with relative movement between the ceramic vane piece and the structural platform such that there is a range of radial and axial motion;

a seal having a radial leg and an axial leg, the radial leg extending in the radial seal slot and the axial leg extending in the interface along the bearing surface; and

a pressure tap opening to the seal, the pressure tap providing a pressurized fluid biasing the seal toward a seated sealing position against the radial seal slot and the bearing surface over the range of radial and axial motion.

9. The vane as recited in claim 8 , wherein the axial leg defines an axial length, the radial leg defines a radial length, and the axial length is greater than the radial length.

10. The vane as recited in claim 9 , wherein the seal includes a filet that joins the radial leg and the axial leg such that the seal has an L-shaped cross-section.

11. The vane as recited in claim 10 , wherein the radial leg extends from the filet to a tip edge, and the tip edge has a concavity.

12. The vane as recited in claim 11 , wherein the structural platform defines a purge hole that opens at the radial seal slot and exits over the concavity.

13. The vane as recited in claim 10 , wherein the seal is formed of a metallic material and has a thickness of 0.15 millimeters to 0.28 millimeters.

14. The vane as recited in claim 8 , wherein the structural platform further comprises an axial seal slot extending from the radial seal slot.

15. The vane as recited in claim 8 , wherein the radial leg and the axial leg form an angle of 60° to 105°.

16. A method for assembling a vane, the method comprising:

providing a structural platform that defines a radial seal slot and a ceramic vane piece that defines first and second vane platforms and a hollow airfoil section that joins the first and second vane platforms; and

introducing a seal between the structural platform and the first vane platform such that a radial leg of the seal extends in the radial seal slot and an axial leg of the seal extends in an interface between the structural platform and the first vane platform, the seal includes a filet that joins the radial leg and the axial leg such that the seal has an L-shaped cross-section, the radial leg extends from the filet to a tip edge and the tip edge has a concavity, and the structural platform defines a purge hole that opens at the radial seal slot and exits over the concavity.

17. The method as recited in claim 16 , wherein the axial leg defines an axial length, the radial leg defines a radial length, the axial length is greater than the radial length, and the seal includes a filet that joins the radial leg and the axial leg such that the seal has an L-shaped cross-section.