US-20260126010-A1 - OPEN ROTOR NOSE CONE RAM AIR HEAT EXCHANGER WITH EXHAUST OF COOLING AIR THROUGH STATIC STRUCTURE

US20260126010A1US 20260126010 A1US20260126010 A1US 20260126010A1US-20260126010-A1

Abstract

A gas turbine engine includes an open rotor configured to rotate with a nose cone. A heat exchanger is positioned within the nose cone and a system for using a working fluid. An inlet from the system is connected to the heat exchanger and an outlet from the heat exchanger connected back to the system. A central opening is in a central portion of the nose cone to deliver cooling air across the heat exchanger, and a duct downstream of the heat exchanger to direct the cooling air radially to at least one static opening such that the cooling air can move radially outwardly through static structure and be directed into a propulsion airflow path. A method and a heat exchange system are also disclosed.

Inventors

William K. Ackermann

Assignees

RTX CORPORATION

Dates

Publication Date: 20260507
Application Date: 20260106

Claims (20)

1 . A gas turbine engine comprising: an open rotor configured to rotate with a nose cone; a heat exchanger positioned within the nose cone and a system for using a working fluid, an inlet from the system connected to the heat exchanger and an outlet from the heat exchanger connected back to the system; a central opening in a central portion of the nose cone to deliver cooling air across the heat exchanger, and a duct downstream of the heat exchanger to direct the cooling air radially to at least one static opening such that the cooling air can move radially outwardly through static structure and be directed into a propulsion airflow path; a door operable to selectively block airflow into the central opening in a closed position, or allow airflow into the central opening in an open position; and wherein an actuator drives the door between the open and closed positions.
2 . The gas turbine engine as set forth in claim 1 , wherein the open rotor is driven by a gear reduction such that it rotates at a slower speed than a propulsor drive turbine of the gas turbine engine.
3 . The gas turbine engine as set forth in claim 1 , wherein the central opening in the nose cone directs air into a diffuser.
4 . The gas turbine engine as set forth in claim 1 , further comprising an exit manifold downstream of the heat exchanger.
5 . The gas turbine engine as set forth in claim 4 , wherein downstream of the exit manifold the cooling air is connected into a connecting duct which turns it in a radially outward direction.
6 . The gas turbine engine as set forth in claim 1 , wherein a swirl recovery vane is positioned downstream of the open rotor on an outer housing enclosing a core engine including a propulsor drive turbine of the gas turbine engine.
7 . The gas turbine engine as set forth in claim 1 , further comprising: a compressor section; and a turbine section; wherein the outer housing surrounds the compressor section and the turbine section and the at least one static opening is located in the outer housing.
8 . The gas turbine engine as set forth in claim 7 , wherein the at least one static opening is downstream of the open rotor.
9 . The gas turbine engine as set forth in claim 7 , wherein the cooling air is connected through static struts radially inward of the outer housing.
10 . The gas turbine engine as set forth in claim 1 , wherein the heat exchanger is at least one of: rectangular; circular; arc-shaped; or cylindrical.
11 . The gas turbine engine as set forth in claim 1 , wherein the heat exchanger is cylindrical and includes a central channel through which ambient air is received and passed through the heat exchanger.
12 . The gas turbine engine as set forth in claim 1 , wherein the heat exchanger is cylindrical and has an outer wall that surrounds an inner cylinder, with a flow channel defined between the inner cylinder and the outer wall.
13 . A method of operating a gas turbine engine comprising the steps of: 1) driving a gas turbine engine to rotate a nose cone, the nose cone having a central opening; 2) passing a working fluid through a heat exchanger received in the nose cone; 3) passing air into the central opening and across the heat exchanger to cool the working fluid; 4) passing the air downstream of the heat exchanger outwardly through static structure on the gas turbine engine through at least one static opening; and 5) controlling a door to selectively open and close the central opening.
14 . The method as set forth in claim 13 , wherein an outer housing surrounds a compressor section and a turbine section and the at least one static opening is located in the outer housing.
15 . A gas turbine engine comprising: an open rotor configured to rotate with a nose cone; a heat exchanger positioned within the nose cone and a system for using a working fluid, an inlet from the system connected to the heat exchanger and an outlet from the heat exchanger connected back to the system; a central opening in a central portion of the nose cone to deliver cooling air across the heat exchanger, and a duct downstream of the heat exchanger to direct the cooling air radially to at least one static opening such that the cooling air can move radially outwardly through static structure and be directed into a propulsion airflow path; and further comprising: a compressor section; and a turbine section; wherein the outer housing surrounds the compressor section and the turbine section and the at least one static opening is located in the outer housing; and wherein the at least one static opening is downstream of the open rotor.
16 . The gas turbine engine as set forth in claim 15 , wherein the open rotor is driven by a gear reduction such that it rotates at a slower speed than a propulsor drive turbine of the gas turbine engine.
17 . The gas turbine engine as set forth in claim 15 , wherein the central opening in the nose cone directs air into a diffuser.
18 . The gas turbine engine as set forth in claim 15 , further comprising an exit manifold downstream of the heat exchanger.
19 . The gas turbine engine as set forth in claim 18 , wherein downstream of the exit manifold the cooling air is connected into a connecting duct which turns it in a radially outward direction.
20 . The gas turbine engine as set forth in claim 15 , wherein a swirl recovery vane is positioned downstream of the open rotor on an outer housing enclosing a core engine including a propulsor drive turbine of the gas turbine engine.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 18/934,682 filed Nov. 1, 2024, which claims the benefit of U.S. Provisional Patent Application No. 63/597,444 filed Nov. 9, 2023; the disclosure of which is incorporated by reference in its entirety herein. BACKGROUND OF THE INVENTION This application relates to a gas turbine engine having an open rotor propulsor, and a heat exchanger in a nose cone. Gas turbines are known, and typically include a propulsor delivering air as propulsion external to a core engine, and also delivering air into the core engine. The air in the core engine passes into a compressor section. Compressed air is delivered into a combustor where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors, driving them to rotate. It is known that there are accessory systems associated with gas turbine engines. As an example, a lubrication system and cooling air systems are typically required. It is also known that the working fluid of those systems becomes hot and it is desirable to provide a heat exchanger to cool the working fluid. One type of turbine engine utilizes a fan (e.g., turbofan). A fan is provided with an outer housing, and thus the propulsion air flows into a bypass duct defined by the outer housing and an inner housing. This bypass air may be a source of cooling air for a heat exchanger as it is pressurized. However, another type of gas turbine engine utilizes an open rotor propulsor and, with such a system, obtaining cooling air can be a challenge. The air is not pressurized due to the absence of an outer housing. SUMMARY OF THE INVENTION In a featured embodiment, a gas turbine engine includes an open rotor configured to rotate with a nose cone. A heat exchanger is positioned within the nose cone and a system for using a working fluid. An inlet from the system is connected to the heat exchanger and an outlet from the heat exchanger connected back to the system. A central opening is in a central portion of the nose cone to deliver cooling air across the heat exchanger, and a duct downstream of the heat exchanger to direct the cooling air radially to at least one static opening such that the cooling air can move radially outwardly through static structure and be directed into a propulsion airflow path. In another embodiment according to the previous embodiment, the open rotor is driven by a gear reduction such that it rotates at a slower speed than a propulsor drive turbine of the gas turbine engine. In another embodiment according to any of the previous embodiments, the central opening in the nose cone directs air into a diffuser. In another embodiment according to any of the previous embodiments, further including an exit manifold downstream of the heat exchanger. In another embodiment according to any of the previous embodiments, downstream of the exit manifold the cooling air is connected into a connecting duct which turns it in a radially outward direction. In another embodiment according to any of the previous embodiments, a swirl recovery vane is positioned downstream of the open rotor on an outer housing enclosing a core engine including a propulsor drive turbine of the gas turbine engine. In another embodiment according to any of the previous embodiments, the at least one static opening is in the swirl recovery vane. In another embodiment according to any of the previous embodiments, the at least one static opening includes a plurality static openings in the swirl recovery vane. In another embodiment according to any of the previous embodiments, at least one of the plurality of static opening is located at a radially outer end of the swirl recovery vane. In another embodiment according to any of the previous embodiments, further includes a compressor section and a turbine section. The outer housing surrounds the compressor section and the turbine section and the at least one static opening is located in the outer housing. In another embodiment according to any of the previous embodiments, the at least one static opening is downstream of the open rotor. In another embodiment according to any of the previous embodiments, the cooling air is connected through static struts radially inward of the outer housing. In another embodiment according to any of the previous embodiments, further includes a door operable to selectively block airflow into the central opening in a closed position, or allow airflow into the central opening in an open position. In another embodiment according to any of the previous embodiments, an actuator drives the door between the open and closed positions. In another embodiment according to any of the previous embodiments, the heat exchanger is a at least one of rectangular, circular, arc-shaped or cylindrical. In another embodiment according to any of the previous embodiments, the heat exchanger is cylindrical and includes a central channel through