Generators with open loop active cooling

1. A generator, comprising:

(a) an inner body defining:

(1) a longitudinal axis;

(2) an interior surface and an opposed exterior surface; and

(3) a coolant inlet and a coolant outlet extending between the interior and exterior surfaces of the inner body;

(b) an outer body arranged outboard of the inner body, wherein the inner and outer bodies define a cooling path having (i) an interior cooling path bounded by the inner body interior surface and fluidly coupling the coolant inlet to the coolant outlet, and (ii) an exterior exhaust path bounded by the inner body exterior surface and outer body interior surface for fluidly coupling the coolant outlet to the external environment of the generator, wherein the outer body is configured for rotation about the longitudinal axis of the inner body; and

(c) a cryogenic fuel supply in fluid communication with the coolant inlet.

2. The generator as recited in claim 1 , wherein the coolant inlet is configured to fluidly couple the rotor body to a cryogenic fuel supply.

3. The generator as recited in claim 1 , wherein the coolant inlet is configured to fluidly couple the rotor body to a hydrogen, oxygen, xenon, or helium supply.

4. The generator as recited in claim 1 , further comprising a baffle coupled to the rotor body inner surface and dividing an interior cavity of the rotor body into a plurality of coolant channels extending between the coolant inlet and the coolant outlet.

5. The generator as recited in claim 4 , wherein the sidewall intersects a longitudinal axis of the rotor body obliquely such that the coolant outlet is oriented toward a first end portion of the rotor body.

6. The generator as recited in claim 4 , wherein the sidewall intersects a longitudinal axis of the rotor body obliquely such that the coolant outlet is oriented toward a second end portion of the rotor body.

7. The generator as recited in claim 4 , wherein the sidewall defines a coolant outlet axis oriented radially outward and towards a direction of rotation of the rotor body.

8. The generator as recited in claim 4 , wherein the sidewall defines a coolant outlet axis oriented radially outward and opposite a direction of rotation of the rotor body.

9. The generator as recited in claim 1 , wherein the rotor body defines a plurality of coolant outlets disposed along an axial length of the rotor body.

10. The generator as recited in claim 1 , wherein the rotor body defines a plurality of coolant outlets disposed about a circumference of the rotor body.

11. The generator as recited in claim 1 , wherein the coolant outlet is bounded by a sidewall extending between the interior and exterior surfaces of the rotor body through a thickness of the rotor body.

12. The generator as recited in claim 1 , wherein the generator is a turbo-alternator.

13. The generator as recited in claim 12 , wherein the coolant inlet is configured to cool bearings supporting the rotor body using coolant flow traversing the coolant inlet.

14. The generator as recited in claim 13 , wherein the cooling path includes a speed control valve fluidly coupled between the supply orifice and the coolant inlet of the rotor body.

15. The generator as recited in claim 14 , wherein the speed control valve is fluidly coupled to the rotor body through a first coolant inlet and a second coolant inlet.

16. The generator as recited in claim 15 , wherein the first and second coolant inlets are arranged on opposite ends of the rotor body.

17. A generator as recited in claim 1 , wherein the generator is configured for active cooling by receiving a pressurized fuel flow from a space vehicle fuel system.

18. A generator as recited in claim 17 , wherein the fuel is liquid hydrogen.

19. A generator as recited in claim 17 , wherein the coolant outlet is fluidly coupled to an external environment for open loop cooling of the generator.