Dynamic live hinge spring optimized impeller

1. An impeller comprising:

a hub;

a shroud comprising:

a cylindrical portion defining a fluid inlet, the cylindrical portion coaxial with a rotational axis of the impeller;

the shroud extending radially outward and downstream from the cylindrical portion and covering the hub;

a plurality of vanes connected to and extending between the shroud and the hub;

a fluid outlet downstream of the plurality of vanes, such that a fluid flow direction through the impeller is defined from the fluid inlet, past the plurality of vanes, to the fluid outlet;

a plurality of doors disposed circumferentially about the cylindrical portion proximate the inlet; and

a spring element attached to and disposed between each of the plurality of doors and the cylindrical portion,

wherein each of the plurality of doors is actuatable, via the spring element, between a first state and a second state.

2. The impeller of claim 1 wherein in the first state, the plurality of doors defines a first inlet area, and wherein in the second state, the plurality of doors defines a second inlet area different than the first inlet area.

3. The impeller of claim 2 , wherein the second inlet area is greater than the first inlet area.

4. The impeller of claim 2 and further comprising: a hinge interconnecting each of the plurality of doors to the cylindrical portion.

5. The impeller of claim 4 , wherein the hinge is a single annular structure interconnecting each of the plurality of doors to the cylindrical portion.

6. The impeller of claim 4 , wherein the plurality of actuatable doors, the hinge, and the spring elements are formed from a metallic material.

7. The impeller of claim 6 , wherein the impeller is formed from the metallic material.

8. The impeller of claim 7 , wherein the metallic material is one of aluminum, stainless steel, and a nickel alloy.

9. The impeller of claim 2 , wherein:

in the first state, each of the plurality of doors s angled away from the cylindrical portion a first angle; and

in the second state, each of the plurality of doors is angled away from the cylindrical portion a second angle.

10. The impeller of claim 9 , wherein the first angle is greater than the second angle.

11. The impeller of claim 2 , wherein each spring element has an arcuate shape.

12. The impeller of claim 2 , wherein each of the plurality of vanes comprises:

a first region proximate the hub and aerodynamically optimized for a first flow regime of the fluid; and

a second region proximate the shroud and aerodynamically optimized for a second, higher flow regime of the fluid.

13. A method of operating the impeller of claim 1 , the method comprising:

introducing a fluid flow to the fluid inlet;

rotating the impeller about the rotational axis to accelerate a fluid flow across the plurality of vanes and through the fluid outlet; and

varying an area of the fluid inlet by varying a speed and pressure of the fluid flow on the plurality of doors such that the plurality of doors s actuated between the first state and the second state.

14. The method of claim 13 , wherein at a first speed and pressure of the fluid flow, the plurality of doors is in the first state defining a first inlet area.

15. The method of claim 14 and further comprising: increasing the speed and pressure of the fluid flow to actuate the plurality of doors to the second state defining a second inlet area, the second inlet area being greater than the first inlet area.

16. The method of claim 15 , wherein actuating the plurality of doors to the second state comprises deforming a spring element connected to each of the plurality of doors.

17. The method of claim 14 , wherein actuating the plurality of doors to the second state further comprises pivoting the plurality of doors about a hinge.

18. The method of claim 15 , wherein in the first state, the fluid flow impinges upon a region of at least a subset of the plurality of vanes proximate the hub.

19. The method of claim 18 , wherein in the second state, the fluid flow impinges upon a region of at least a subset of the plurality of vanes proximate the shroud.

20. The method of claim 19 , wherein the fluid is a liquid.