Fluid cooling systems for a gas turbine engine

1. A heat exchanger comprising:

an airfoil configured to be positioned in a coolant stream, said airfoil comprising:

a pressure sidewall; and

a suction sidewall coupled to said pressure sidewall, said suction sidewall and said pressure sidewall define a leading edge, a trailing edge opposite said leading edge, a root portion, and a tip portion opposite said root portion, said leading edge defines an impingement zone wherein the coolant stream is configured to impinge said airfoil; and

at least one channel defined within said airfoil between said pressure sidewall and said suction sidewall, said at least one channel at least partially defined within the impingement zone proximate said leading edge, said at least one channel comprising:

an inlet section extending from said root portion to adjacent said tip portion within said airfoil, said inlet section comprising a conical shape that tapers from said root portion towards said tip portion;

an outlet section extending from adjacent said tip portion to said root portion, said outlet section comprising a conical shape that tapers from said root portion towards said tip portion; and

at least one middle section defined within said airfoil and fluidly connecting said inlet section to said outlet section, wherein said at least one channel is configured to channel a fluid through said root portion into said inlet section and channel the fluid from said outlet section through said root portion, and wherein said at least one channel is configured to contain the fluid within said airfoil after the fluid enters into said inlet section until the fluid exits out of said outlet section.

2. The heat exchanger in accordance with claim 1 , wherein said at least one channel is configured such that heat is removed from the fluid at least in part through the coolant stream impinging on said leading edge.

3. The heat exchanger in accordance with claim 1 , wherein said leading edge and said trailing edge define a chord direction, and wherein said at least one middle section extends along the chord direction from said inlet section to said outlet section adjacent at least one of said pressure sidewall and said suction sidewall.

4. The heat exchanger in accordance with claim 3 , wherein said inlet section is adjacent said suction sidewall.

5. The heat exchanger in accordance with claim 3 , wherein said outlet section is adjacent said pressure sidewall.

6. The heat exchanger in accordance with claim 3 , wherein said at least one middle section is substantially parallel to said tip portion and said root portion.

7. The heat exchanger in accordance with claim 3 , wherein said at least one middle section extends at a slope along the chord direction.

8. The heat exchanger in accordance with claim 3 , wherein said at least one middle section extends from said inlet section to said leading edge adjacent said suction sidewall and from said leading edge to said outlet section adjacent said pressure sidewall.

9. The heat exchanger in accordance with claim 1 , wherein said at least one middle section comprises a plurality of discrete middle sections, each discrete middle section individually fluidly connecting said inlet section to said outlet section.

10. The heat exchanger in accordance with claim 6 , wherein said at least one middle section comprises a plurality of discrete middle sections, each discrete middle section individually fluidly connecting said inlet section to said outlet section and each discrete middle section parallel to every other discrete middle section across an entire length of each discrete middle section from said inlet section to said outlet section.

11. The heat exchanger in accordance with claim 10 , wherein each discrete middle section has a substantially similar cross-sectional area compared to every other discrete middle section.

12. An outlet guide vane comprising:

an airfoil configured to be positioned in a coolant stream, said airfoil comprising:

a pressure sidewall; and

a suction sidewall coupled to said pressure sidewall, said suction sidewall and said pressure sidewall define a leading edge, a trailing edge opposite said leading edge, a root portion, and a tip portion opposite said root portion, said leading edge defines an impingement zone wherein the coolant stream is configured to impinge said airfoil; and

a heat exchanger comprising at least one channel defined within said airfoil between said pressure sidewall and said suction sidewall, said at least one channel at least partially defined within the impingement zone proximate said leading edge, said at least one channel comprising:

an inlet section extending from said root portion to adjacent said tip portion within said airfoil, said inlet section comprising a conical shape that tapers from said root portion towards said tip portion;

an outlet section extending from adjacent said tip portion to said root portion, said outlet section comprising a conical shape that tapers from said root portion towards said tip portion; and

at least one middle section defined within said airfoil and fluidly connecting said inlet section to said outlet section, wherein said at least one channel is configured to channel a fluid through said root portion into said inlet section and channel the fluid from said outlet section through said root portion, and wherein said at least one channel is configured to contain the fluid within said airfoil after the fluid enters into said inlet section until the fluid exits out of said outlet section.

13. The outlet guide vane in accordance with claim 12 , wherein said leading edge and said trailing edge define a chord direction, and wherein said at least one middle section extends along the chord direction from said inlet section to said outlet section adjacent at least one of said pressure sidewall and said suction sidewall.

14. The outlet guide vane in accordance with claim 12 , wherein said at least one middle section comprises a plurality of discrete middle sections, each discrete middle section individually fluidly connecting said inlet section to said outlet section.

15. The outlet guide vane in accordance with claim 13 , wherein said at least one middle section comprises a plurality of discrete middle sections, each discrete middle section individually fluidly connecting said inlet section to said outlet section and each discrete middle section parallel to every other discrete middle section across an entire length of each discrete middle section from said inlet section to said outlet section.

16. A turbofan engine comprising:

a core engine;

a bypass duct at least partially extending about said core engine; and

a plurality of circumferentially spaced outlet guide vanes extending between said core engine and said bypass duct, at least one outlet guide vane of said plurality of outlet guide vanes comprising:

an airfoil comprising:

a pressure sidewall; and

a suction sidewall coupled to said pressure sidewall, said suction sidewall and said pressure sidewall define a leading edge, a trailing edge opposite said leading edge, a root portion, and a tip portion opposite said root portion, said leading edge defines an impingement zone wherein a coolant stream is configured to impinge said airfoil; and

a heat exchanger comprising at least one channel defined within said airfoil between said pressure sidewall and said suction sidewall, said at least one channel at least partially defined within the impingement zone proximate said leading edge, said at least one channel comprising:

an inlet section extending from said root portion to adjacent said tip portion within said airfoil, said inlet section comprising a conical shape that tapers from said root portion towards said tip portion;

an outlet section extending from adjacent said tip portion to said root portion, said outlet section comprising a conical shape that tapers from said root portion towards said tip portion; and

at least one middle section defined within said airfoil and fluidly connecting said inlet section to said outlet section, wherein said at least one channel is configured to channel a fluid through said root portion into said inlet section and channel the fluid from said outlet section through said root portion, and wherein said at least one channel is configured to contain the fluid within said airfoil after the fluid enters into said inlet section until the fluid exits out of said outlet section.

17. The turbofan engine in accordance with claim 16 , wherein said leading edge and said trailing edge define a chord direction, and wherein said at least one middle section extends along the chord direction from said inlet section to said outlet section adjacent at least one of said pressure sidewall and said suction sidewall.

18. The turbofan engine in accordance with claim 16 , wherein said at least one middle section comprises a plurality of discrete middle sections, each discrete middle section individually fluidly connecting said inlet section to said outlet section.

19. The turbofan engine in accordance with claim 17 , wherein said at least one middle section comprises a plurality of discrete middle sections, each discrete middle section individually fluidly connecting said inlet section to said outlet section and each discrete middle section parallel to every other discrete middle section across an entire length of each discrete middle section from said inlet section to said outlet section.