Fluid injection systems for gas turbine engines

1. A fluid injection system of a gas turbine engine, comprising:

a fluid injector configured to inject water into an exhaust flow exiting a turbine section of the gas turbine engine, wherein the fluid injector is coupled to an aft end of a turbine exit guide vane;

a fluid supply tank fluidly coupled to the fluid injector;

a conduit fluidly coupling the fluid supply tank to the fluid injector; and

a heat exchanger thermally coupled to the conduit.

2. The fluid injection system of claim 1 , wherein the conduit is located proximate a fan exit vane.

3. The fluid injection system of claim 1 , further comprising a fuel cell fluidly coupled to the fluid supply tank.

4. The fluid injection system of claim 1 , further comprising:

a valve configured to regulate a flow of the water from the fluid injector;

an electromechanical actuator operably coupled to the valve; and

a controller in operable communication with the electromechanical actuator, wherein the controller is configured to command the electromechanical actuator to actuate the valve to an open position during a take-off operating condition.

5. The fluid injection system of claim 1 , wherein the fluid injector includes a plurality of nozzles located along the aft end of the turbine exit guide vane.

6. A gas turbine engine, comprising:

a turbine;

an exhaust system aft of the turbine, the exhaust system comprising a throat and a primary nozzle located radially outward of the throat; and

a fluid injection system configured to inject a fluid into an exhaust gas exiting the turbine, the fluid being configured to evaporate without combusting and decrease a temperature of the exhaust gas exiting the turbine, wherein the fluid injection system comprises a fluid injector having a plurality of nozzles coupled to an aft end of a turbine exit guide vane of the turbine, the turbine exit guide vane and the fluid injector being located at a forward end of the exhaust system.

7. The gas turbine engine of claim 6 , wherein the fluid injection system further comprises a conduit fluidly coupling a fluid supply to the fluid injector, and wherein the conduit is located proximate a fan exit guide vane located forward of the turbine.

8. The gas turbine engine of claim 6 , wherein the fluid injection system further comprises:

a conduit fluidly coupling a fluid supply to the fluid injector; and

a heat exchanger thermally coupled to the conduit.

9. The gas turbine engine of claim 6 , wherein the fluid injection system further comprises a conduit fluidly coupling a fluid supply to the fluid injector, and wherein the conduit is located through a pylon mounted to the gas turbine engine.

10. The gas turbine engine of claim 6 , wherein the fluid injection system further comprises:

a fluid supply fluidly coupled to the fluid injector; and

a fuel cell fluidly coupled to the fluid supply.

11. The gas turbine engine of claim 6 , wherein the fluid injection system further comprises:

a fluid supply fluidly coupled to the fluid injector; and

an aircraft thermal management system fluidly coupled to the fluid supply.

12. The gas turbine engine of claim 6 , wherein the fluid injection system further comprises:

a valve configured to regulate a flow of the fluid from the fluid injector;

an electromechanical actuator operably coupled to the valve; and

a controller in operable communication with the electromechanical actuator, wherein the controller is configured to command the electromechanical actuator to actuate the valve to an open position during a take-off operating condition.

13. A gas turbine engine, comprising:

a turbine section;

an exhaust system aft of the turbine section, comprising a throat and a primary nozzle located radially outward of the throat, wherein a radially inward surface of the primary nozzle defines a portion of a first exhaust path for a core airflow, and wherein a radially outward surface of the primary nozzle defines a portion of a second exhaust path for a bypass airflow; and

a means for injecting a fluid into the core airflow exiting the turbine section, wherein the fluid is configured to decrease a temperature of the core airflow exiting the turbine section upon the fluid being injected into the core airflow exiting the turbine section, such that the temperature of the core airflow exiting the turbine section is greater than a temperature of the core airflow at a forward end of the exhaust system.

14. The gas turbine engine of claim 13 , wherein the fluid is water.

15. The gas turbine engine of claim 13 , wherein the means for injecting the fluid is configured to inject the fluid at a turbine exit guide vane located at an aft end of the turbine section, and wherein the fluid is configured to evaporate without combusting upon being injected into the core airflow.

16. The gas turbine engine of claim 15 , wherein the means for injecting the fluid comprises:

a fluid injection nozzle coupled to the turbine exit guide vane; and

a fluid supply fluidly coupled the fluid injection nozzle.

17. The gas turbine engine of claim 16 , further comprising a means for regulating a flow of the fluid from the fluid injection nozzle.

18. A fluid injection system of a gas turbine engine, comprising:

a fluid injector configured to inject water into an exhaust flow exiting a turbine section of the gas turbine engine, wherein the fluid injector is coupled to an aft end of a turbine exit guide vane;

a valve configured to regulate a flow of the water from the fluid injector;

an electromechanical actuator operably coupled to the valve; and

a controller in operable communication with the electromechanical actuator, wherein the controller is configured to command the electromechanical actuator to actuate the valve to an open position during a take-off operating condition.