Variable infrared suppression system in a gas turbine engine

Patent metadata

Field	Value
Publication number	US-10544755-B2
Application number	US-201615270903-A
Country	US
Kind code	B2
Filing date	Sep 20, 2016
Priority date	Sep 20, 2016
Publication date	Jan 28, 2020
Grant date	Jan 28, 2020

Abstract

According to one aspect, an infrared suppression system that utilizes a primary airflow and a secondary air flow for a gas turbine engine is provided. The infrared suppression system includes an exit flap configured to control a flow of exhaust air out of the gas turbine engine and a secondary flow door that is configured to selectively control the secondary air flow into the gas turbine engine. The mixture of the secondary air flow and the primary air flow from the gas turbine engine suppresses an infrared signature produced by the gas turbine engine.

First claim

We claim:

1. An infrared suppression system that utilizes a primary airflow and a secondary air flow for a gas turbine engine, comprising:
an exit flap configured to control a flow of exhaust air out of the gas turbine engine;
a secondary flow door configured to selectively control the secondary air flow from outside of the gas turbine engine into the gas turbine engine; and
a variable mixer element comprising primary lobes and secondary lobes rotatably mounted on a transverse shaft, wherein the secondary air flow from outside of the gas turbine engine is at a substantially lower temperature than a temperature of the primary air flow inside the gas turbine engine, and wherein a mixture of the secondary air flow and the primary air flow from the gas turbine engine suppresses an infrared signature produced by the gas turbine engine.

2. The infrared suppression system of claim 1 , wherein the variable mixer element is configured to variably mix the primary air flow with the secondary air flow.

3. The infrared suppression system of claim 2 , wherein an actuator is configured to open and close the primary lobes and secondary lobes of the variable mixer element.

4. The infrared suppression system of claim 3 , wherein the secondary flow door in a substantially closed position reduces the secondary air flow therethrough and minimizes a mixing of the primary air flow and the secondary air flow.

5. The infrared suppression system of claim 4 , wherein in an intermediate mode at least one of the secondary flow door, the variable mixer element and the exit flap is in a substantially closed position.

6. The infrared suppression system of claim 3 , wherein the secondary flow door in an open position directs the secondary air flow into the primary air flow such that the primary flow and the secondary air flow mix.

7. The infrared suppression system of claim 6 , wherein in an infrared suppression mode each of the secondary flow door, the variable mixer element and the exit flap are in open positions.

8. The infrared suppression system of claim 3 , wherein the actuator is coupled to the secondary air flow door, the variable mixer element, and the exit flap, wherein the actuator operates in a single degree-of-freedom mode by positioning each of the secondary air flow door, the variable mixer element, and the exit flap in only one of an open position and a closed position.

9. The infrared suppression system of claim 8 , wherein the actuator operates in a multiple degrees-of-freedom mode by variably operating the secondary air flow door, the variable mixer element, and the exit flap between a substantially open position and a substantially closed position.

10. A gas turbine engine having an infrared suppression system, comprising:
a secondary flow door configured to control a secondary air flow into an exhaust portion of the gas turbine engine;
an exit flap configured to control a flow of exhaust air out of the gas turbine engine, wherein a level of mixture of a primary air flow inside the gas turbine engine and the secondary air flow from outside of the gas turbine engine causes changes in modes between an infrared suppression mode and a performance mode of the gas turbine engine; and
a variable mixer element comprising a set of primary lobes and a set of secondary lobes coupled to an actuator, the actuator configured to position the variable mixer element in a collapsed position in the performance mode, and wherein the secondary air flow from outside of the gas turbine engine is at a substantially lower temperature than a temperature of the primary air flow inside the gas turbine engine.

11. The gas turbine engine of claim 10 , wherein the variable mixer element is configured to variably mix the primary air flow with the secondary air flow in an expanded position in the infrared suppression mode.

12. The gas turbine engine of claim 11 , wherein the set of primary lobes and the set of secondary lobes respectively direct the primary air flow and the secondary air flow.

13. A gas turbine engine having an infrared suppression system, comprising:
a secondary flow door configured to control a secondary air flow into the gas turbine engine;
an exit flap configured to control a flow of exhaust air out of the gas turbine engine, wherein a level of mixture of the secondary air flow and a primary air flow causes changes in modes between an infrared suppression mode and a performance mode of the gas turbine engine; and
a variable mixer element configured to variably mix the primary air flow with the secondary air flow, wherein the variable mixer element comprises a primary air flow element and a secondary air flow element, wherein in the infrared suppression mode an actuator is configured to position the secondary flow door, the secondary air flow element and the exit flap in open positions.

14. The gas turbine engine of claim 13 , wherein in the performance mode the actuator is configured to position the secondary flow door, the secondary air flow element and the exit flap in closed positions.

15. The gas turbine engine of claim 14 , wherein in an intermediate mode between the infrared suppression mode and the performance mode at least one of the secondary flow door, the secondary air flow element and the exit flap is in a substantially closed position.

16. The gas turbine engine of claim 15 , wherein the actuator is coupled to the secondary air flow door, the secondary air flow element and the exit flap, wherein the actuator operates in multiple degrees-of-freedom mode by variably operating the secondary air flow door, the secondary air flow element, and the exit flap between a substantially open position and the substantially closed position.

17. The gas turbine engine of claim 14 , wherein the actuator operates in a single degree-of-freedom mode by positioning each of the secondary air flow door, the secondary air flow element, and the exit flap in only one of open positions or closed positions.

18. The infrared suppression system of claim 1 , comprising a further variable mixer element mounted opposite the variable mixer element.

19. The gas turbine engine of claim 10 , comprising a further variable mixer element, wherein the variable mixer element is an upper mixer and the further variable mixer element is a lower mixer, wherein the upper mixer comprises an upper linkage and the lower mixer comprises a lower linkage, and wherein the upper linkage the lower linkage are coupled to the actuator.

20. The gas turbine engine of claim 12 , wherein the set of primary lobes and the set of secondary lobes are mounted in an alternating arrangement.

Assignees

• Rolls Royce Nam Tech Inc

Inventors

• Pesyna Kenneth M
• Pierluissi Anthony F

Classifications

• F02K1/825 Primary

  Infrared radiation suppressors · CPC title

• F02K1/46 Primary

  Nozzles having means for adding air to the jet or for augmenting the mixing region between the jet and the ambient air, e.g. for silencing (F02K1/28, F02K1/36, F02K1/38 take precedence) · CPC title

• F02K1/12

  by means of pivoted flaps · CPC title

• F02K1/48

  Corrugated nozzles · CPC title

• B64D2033/045

  comprising infrared suppressors · CPC title