Diffuser

1. A diffuser, comprising:

a cylindrical wall having a first lattice structure formed of a first plurality of triply periodic surfaces that are periodic in cylindrical coordinates, the cylindrical wall having a first end and a second end, opposite the first end, and the first lattice structure having a plurality of passages that extend between an inner surface of the cylindrical wall and an outer surface of the cylindrical wall; and

an arcuate end wall located at the second end of the cylindrical wall and having a second lattice structure formed of a second plurality of triply periodic surfaces that are periodic in spherical coordinates, the second lattice structure having a plurality of passages that extend between an inner surface of the arcuate end wall and an outer surface of the arcuate end wall.

2. The diffuser of claim 1 , wherein the first plurality of triply periodic surfaces and the second plurality of triply periodic surfaces are gyroid.

3. The diffuser of claim 1 , wherein the first plurality of triply periodic surfaces are oriented such that there are no unimpeded linear radial flow paths in the plurality of passages through the cylindrical wall and the second plurality of triply periodic surfaces are oriented such that there are no unimpeded linear radial flow paths in the plurality of passages through the arcuate end wall.

4. The diffuser of claim 1 , wherein the diffuser is an inline diffuser and comprises a first flange adjacent the first end of the cylindrical wall, an outlet head adjacent the outer surface of the cylindrical wall and secured to the cylindrical wall, and a second flange attached to the outlet head.

5. A diffuser, comprising:

a first wall having a first lattice structure formed of a first plurality of triply periodic surfaces, the first lattice structure having a plurality of passages that extend between an inner surface of the first wall and an outer surface of the first wall;

a second wall having a second lattice structure formed of a second plurality of triply periodic surfaces, the second lattice structure having a plurality of passages that extend between an inner surface of the second wall and an outer surface of the second wall; and

an annular cavity separating the first wall and the second wall.

6. The diffuser of claim 5 , wherein the first lattice structure has a different volume fraction than the second lattice structure.

7. The diffuser of claim 5 , wherein the first lattice structure has a different unit cell size than the second lattice structure.

8. The diffuser of claim 5 , wherein:

the first wall is cylindrical and the first plurality of triply periodic surfaces are periodic in cylindrical coordinates; and

the second wall is cylindrical and the second plurality of triply periodic surfaces are periodic in cylindrical coordinates.

9. The diffuser of claim 8 , comprising:

a first arcuate end wall located at a second end of the first wall and having a third lattice structure formed of a third plurality of triply periodic surfaces that are periodic in spherical coordinates, the third lattice structure having a plurality of passages that extend between an inner surface of the first arcuate end wall and an outer surface of the first arcuate end wall; and

a second arcuate end wall located at a second end of the second wall and having a fourth lattice structure formed of a fourth plurality of triply periodic surfaces that are periodic in spherical coordinates, the fourth lattice structure having a plurality of passages that extend between an inner surface of the second arcuate end wall and an outer surface of the second arcuate end wall.

10. The diffuser of claim 5 , wherein:

the first wall is arcuate and the first plurality of triply periodic surfaces are periodic in spherical coordinates; and

the second wall is arcuate and the second plurality of triply periodic surfaces are periodic in spherical coordinates.

11. The diffuser of claim 5 , wherein:

the first wall is cylindrical and the first plurality of triply periodic surfaces are periodic in cylindrical coordinates; and

the second wall is spherical and the second plurality of triply periodic surfaces are periodic in spherical coordinates.

12. The diffuser of claim 5 , wherein the first plurality of triply periodic surfaces and the second plurality of triply periodic surfaces are gyroid.

13. The diffuser of claim 5 , wherein the first plurality of triply periodic surfaces are oriented such that there are no unimpeded linear radial flow paths in the plurality of passages through the first wall and the second plurality of triply periodic surfaces are oriented such that there are no unimpeded linear radial flow paths in the plurality of passages through the second wall.

14. A diffuser, comprising:

a wall having a lattice structure formed of a plurality of triply periodic surfaces, the lattice structure having a plurality of passages that extend between an inner surface of the wall and an outer surface of the wall; wherein

the lattice structure has a varying unit cell size.

15. The diffuser of claim 14 , wherein the wall is cylindrical and the triply periodic surfaces are periodic in cylindrical coordinates.

16. The diffuser of claim 15 , wherein the unit cell size of the lattice structure changes from the inner surface of the wall to the outer surface.

17. The diffuser of claim 15 , wherein the wall is cylindrical and the unit cell size of the lattice structure changes from a first end of the wall to a second end of the wall.

18. The diffuser of claim 15 , comprising:

an arcuate end wall located at a second end of the wall and having a second lattice structure formed of a second plurality of triply periodic surfaces that are periodic in spherical coordinates, the second lattice structure having a plurality of passages that extend between an inner surface of the arcuate end wall and an outer surface of the arcuate end wall; wherein

a unit cell size of the second lattice structure changes from the inner surface of the arcuate end wall to the outer surface of the arcuate end wall.

19. The diffuser of claim 14 , wherein the wall is spherical and the triply periodic surfaces are periodic in spherical coordinates.

20. The diffuser of claim 19 , wherein the unit cell size of the lattice structure changes from the inner surface of the wall to the outer surface.