Abstract: A heat exchanger includes a body, a plurality of first flow channels defined in the body; and a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. The first flow channels and second flow channels are arranged in a checkerboard pattern.

Abstract: A fuel system for a gas turbine engine includes a main fuel pump generating a main fuel flow into a main fuel passage and a secondary pump generating a secondary fuel flow into a secondary flow passage. A first control valve is disposed in a passage between the main fuel passage and the secondary flow passage. The first control valve selectively directs an excess portion of the main fuel flow to the secondary flow passage to provide at least a portion of the secondary fuel flow.

Abstract: A fuel system for a gas turbine engine includes a main fuel pump generating a main fuel flow into a main fuel passage and a secondary pump generating a secondary fuel flow into a secondary flow passage. A first control valve is disposed in a passage between the main fuel passage and the secondary flow passage. The first control valve selectively directs an excess portion of the main fuel flow to the secondary flow passage to provide at least a portion of the secondary fuel flow.

Abstract: A heat exchanger includes a body, a plurality of first flow channels defined in the body; and a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. The first flow channels and second flow channels are arranged in a checkerboard pattern.

Abstract: A heat exchanger includes a body, a plurality of first flow channels defined in the body; and a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. The first flow channels and second flow channels are arranged in a checkerboard pattern.

Abstract: A gas turbine engine includes a main compressor section and a main turbine section. A cooling air supply system cools a location in at least one of the main compressor section and the main turbine section. The cooling air supply system includes a tap for tapping cooling air compressed by the main compressor section, connected for passing the cooling air through a heat exchanger and to a boost compressor, and then to the cooling location in the at least one of the main compressor section and the main turbine section. A fuel supply system has a fuel tank for delivering fuel to a fuel pump. At least one valve for selectively returning fuel downstream of the main pump back to an upstream location. At least one return turbine drives at least one fluid moving device in the air cooling system.

Abstract: A gas turbine engine includes a main compressor section and a main turbine section. A cooling air supply system cools a location in at least one of the main compressor section and the main turbine section. The cooling air supply system includes a tap for tapping cooling air compressed by the main compressor section, connected for passing the cooling air through a heat exchanger and to a boost compressor, and then to the cooling location in the at least one of the main compressor section and the main turbine section. A fuel supply system has a fuel tank for delivering fuel to a fuel pump. At least one valve for selectively returning fuel downstream of the main pump back to an upstream location. At least one return turbine drives at least one fluid moving device in the air cooling system.

Abstract: A fuel system for a gas turbine engine includes a main fuel pump generating a main fuel flow into a main fuel passage and a secondary pump generating a secondary fuel flow into a secondary flow passage. A first control valve is disposed in a passage between the main fuel passage and the secondary flow passage. The first control valve selectively directs an excess portion of the main fuel flow to the secondary flow passage to provide at least a portion of the secondary fuel flow.

Abstract: A lower pressure tap is connected to a first heat exchanger to be cooled by cooling air, and then to a selection valve. The selection valve selectively delivers the lower pressure tap air to a boost compressor. The lower pressure tap air downstream of the boost compressor is connected to cool the at least one turbine. The selection valve also selectively delivers a portion of the lower pressure tap air across a first cooling turbine, and to a line associated with an air delivery system for a cabin on an associated aircraft. A portion of the air downstream of the first cooling turbine is connected to a second cooling turbine, and air downstream of the second cooling turbine is connected for use in a cold loop A method of operating an air supply system is also disclosed.

Abstract: A heat exchanger system includes an additively manufactured inlet header upstream of, and in fluid communication with, the heat exchanger core and an additively manufactured exit header downstream of, and in fluid communication with, the heat exchanger core. A method of manufacturing a header for a ducted heat exchanger system for a gas turbine engine includes additively manufacturing a header with respect to a desired airflow therethrough.

Abstract: A fuel system for a gas turbine engine includes a primary fuel pump providing fuel flow during engine operation and a primary electric motor coupled to the primary fuel pump for driving the primary fuel pump during engine operation. A secondary system provides fuel flow in the absence of fuel flow from the primary fuel pump.

Abstract: A gas turbine engine includes a main compressor section and a main turbine section. A cooling air supply system cools a location in at least one of the main compressor section and the main turbine section. The cooling air supply system includes a tap for tapping cooling air compressed by the main compressor section, connected for passing the cooling air through a heat exchanger and to a boost compressor, and then to the cooling location in the at least one of the main compressor section and the main turbine section. A fuel supply system has a fuel tank for delivering fuel to a fuel pump. At least one valve for selectively returning fuel downstream of the main pump back to an upstream location. At least one return turbine drives at least one fluid moving device in the air cooling system.

Abstract: A lower pressure tap is connected to a first heat exchanger to be cooled by cooling air, and then to a selection valve. The selection valve selectively delivers the lower pressure tap air to a boost compressor. The lower pressure tap air downstream of the boost compressor is connected to cool the at least one turbine. The selection valve also selectively delivers a portion of the lower pressure tap air across a first cooling turbine, and to a line associated with an air delivery system for a cabin on an associated aircraft. A portion of the air downstream of the first cooling turbine is connected to a second cooling turbine, and air downstream of the second cooling turbine is connected for use in a cold loop A method of operating an air supply system is also disclosed.

Abstract: A heat exchanger includes a body, a plurality of first flow channels defined in the body, and a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. At least two of the second flow channels are adjacent each other and are separated from each other by at least one common fin, wherein the at least one common fin includes an opening defined therein for permitting flow between the adjacent second flow channels.

Abstract: A heat exchanger includes a body, a plurality of first flow channels defined in the body; and a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. The first flow channels and second flow channels are arranged in a checkerboard pattern.

Abstract: A heat exchanger includes a body and a plurality of elliptical flow channels defined in the body, the elliptical flow channels defining an elliptical cross-sectional flow area, and a plurality of non-elliptical flow channels defined in the body and interspersed between the elliptical flow channels, the non-elliptical flow channels having a non-elliptical cross-sectional flow area.

Abstract: A heat exchanger system includes an additively manufactured inlet header upstream of, and in fluid communication with, the heat exchanger core and an additively manufactured exit header downstream of, and in fluid communication with, the heat exchanger core. A method of manufacturing a header for a ducted heat exchanger system for a gas turbine engine includes additively manufacturing a header with respect to a desired airflow therethrough.