Heat pipe for a turbine engine

1. An assembly for a turbine engine, comprising:

a turbine engine case comprising a sidewall;

a first turbine engine airfoil connected to the turbine engine case;

a second turbine engine airfoil connected to the turbine engine case; and

a heat pipe configured with the sidewall, the first turbine engine airfoil and the second turbine engine airfoil, the heat pipe comprising a closed-loop internal fluid circuit.

2. The assembly of claim 1 , wherein the first turbine engine airfoil is configured as a vane.

3. The assembly of claim 2 , wherein the vane is a turbine vane or a diffuser vane.

4. The assembly of claim 1 , wherein the heat pipe is formed integral with the first turbine engine airfoil.

5. The assembly of claim 1 , wherein a passage of the heat pipe extends within the first turbine engine airfoil.

6. The assembly of claim 1 , wherein

the heat pipe further comprises a working fluid; and

the heat pipe is configured to circulate the working fluid through the closed-loop internal fluid circuit.

7. The assembly of claim 6 , wherein

the closed-loop internal fluid circuit comprises a first passage and a second passage, the heat pipe is configured to flow the working fluid in a first phase through the first passage, and the heat pipe configured to flow the working fluid in a second phase through the second passage; and

the heat pipe comprises a lattice structure that forms the first passage and the second passage.

8. The assembly of claim 6 , wherein

the closed-loop internal fluid circuit comprises a first passage and a second passage, the heat pipe is configured to flow the working fluid in a first phase through the first passage, and the heat pipe configured to flow the working fluid in a second phase through the second passage; and

the heat pipe comprises a lattice structure within the second passage.

9. The assembly of claim 6 , wherein

the closed-loop internal fluid circuit comprises a first passage and a second passage, the heat pipe is configured to flow the working fluid in a first phase through the first passage, and the heat pipe configured to flow the working fluid in a second phase through the second passage; and

the heat pipe comprises sintered powder within the second passage.

10. The assembly of claim 1 , wherein the heat pipe comprises a working fluid, a gas passage and a liquid passage, and the heat pipe is configured to

transfer heat energy into the working fluid in a liquid phase at a first end of the heat pipe to at least partially change phase of the working fluid into a gaseous phase;

direct the working fluid in the gaseous phase through the gas passage from the first end of the heat pipe to a second end of the heat pipe;

transfer the heat energy out of the working fluid in the gaseous phase at the second end of the heat pipe to at least partially change phase the working fluid into the liquid phase; and

direct the working fluid in the liquid phase through the liquid passage from the second end of the heat pipe to the first end of the heat pipe.

11. The assembly of claim 1 , wherein

the turbine engine case is radially between the turbine engine airfoil and the second turbine engine airfoil; and

a passage of the heat pipe extends out of the turbine engine airfoil, through the sidewall of the turbine engine case, and into the second turbine engine airfoil.

12. The assembly of claim 1 , further comprising thermal insulation surrounding a portion of the heat pipe.

13. An assembly for a turbine engine, comprising:

a first vane;

a second vane;

a turbine engine case between the first vane and the second vane; and

a heat pipe comprising a working fluid and a closed-loop internal fluid circuit that extends through a sidewall of the turbine engine case from the first vane and into the second vane, the heat pipe configured to flow the working fluid through the closed-loop internal fluid circuit.

14. The assembly of claim 13 , wherein the turbine engine case is radially between the first vane and the second vane.

15. An apparatus for a turbine engine, comprising:

a heat pipe extending longitudinally between a first end and a second end;

the heat pipe comprising a working fluid, a gas passage, a liquid passage and a lattice structure in contact with the working fluid in the gas passage and the liquid passage, the heat pipe configured to flow the working fluid in a gaseous phase through the gas passage, and the heat pipe configured to flow the working fluid in a liquid phase through the liquid passage.

16. The apparatus of claim 15 , further comprising:

a turbine engine component;

the gas passage and the liquid passage extending within the turbine engine component.

17. The apparatus of claim 15 , wherein the gas passage and the liquid passage are at least partially formed by and extend through the lattice structure.

18. The apparatus of claim 15 , wherein the lattice structure comprises a Schwarz P-type lattice structure.

19. The apparatus of claim 15 , further comprising:

an inner vane;

an outer vane; and

a structure radially between the inner vane and the outer vane;

the gas passage and the liquid passage extending through the structure and into the inner vane and the outer vane.