A cooling system for an aircraft comprises a gas turbine engine, an ancillary apparatus, and a heat exchanger. The gas turbine engine comprises, in axial flow sequence, a compressor module, a combustor module, and a turbine module, with a first electric machine being rotationally connected to the turbine module. The first electrical machine is configured to generate an electrical power P.sub.EM1 (W). The heat exchanger is configured to transfer a total waste heat energy Q (W) generated by the gas turbine engine and the ancillary apparatus, to an airflow passing through the heat exchanger, and a ratio S of:

[00001]$S=\frac{\left(\mathrm{Total}\mathrm{Electrical}\mathrm{Power}\mathrm{Generated}=P_{\mathrm{EM}1}\right)}{\left(\mathrm{Total}\mathrm{Heat}\mathrm{Energy}\mathrm{Rejected}\mathrm{to}\mathrm{Airflow}=Q\right)}$

is in a range of between 0.50 and 5.00.

A gas turbine engine includes a compressor section with a compressor rotor shaft assembly including a plurality of compressor rotors longitudinally spaced apart from each other via respective ones of a plurality of shaft sections of a rotor shaft, each compressor rotor of the plurality of compressor rotors having a plurality of rotor vanes extending radially outward therefrom and being circumferentially spaced about the compressor rotor. A stator shroud assembly has a stator shroud casing surrounding the compressor rotor shaft assembly, a compressor flow passage being defined between the compressor rotor shaft assembly and the stator shroud casing. A pressurized air source generates a flow of pressurized air to be provided to the compressor section, and a plurality of pressurized airflow nozzles are connected with the pressurized air source and provide the flow of pressurized air into the compressor flow passage to cause the compressor rotor shaft assembly to rotate.

A gas turbine engine includes a compressor section with a compressor rotor shaft assembly including a plurality of compressor rotors longitudinally spaced apart from each other via respective ones of a plurality of shaft sections of a rotor shaft, each compressor rotor of the plurality of compressor rotors having a plurality of rotor vanes extending radially outward therefrom and being circumferentially spaced about the compressor rotor. A stator shroud assembly has a stator shroud casing surrounding the compressor rotor shaft assembly, a compressor flow passage being defined between the compressor rotor shaft assembly and the stator shroud casing. A pressurized air source generates a flow of pressurized air to be provided to the compressor section, and a plurality of pressurized airflow nozzles are connected with the pressurized air source and provide the flow of pressurized air into the compressor flow passage to cause the compressor rotor shaft assembly to rotate.

An aircraft propulsion assembly includes a turbine engine surrounded by a nacelle with an annular air-intake lip extending around the turbine engine by two annular walls, inner and outer, respectively, intended for being swept across by air flows at least when the aircraft is in flight. The inner and outer walls each includes or supports at least one network of pipes forming heat exchangers. The inner wall pipe network having liquid outlet connected with a liquid intake of the outer wall pipe network. The propulsion assembly further includes means for circulating the liquid, connected to at least one liquid intake of the network of pipes of the inner wall.

An aircraft propulsion assembly includes a turbine engine surrounded by a nacelle with an annular air-intake lip extending around the turbine engine by two annular walls, inner and outer, respectively, intended for being swept across by air flows at least when the aircraft is in flight. The inner and outer walls each includes or supports at least one network of pipes forming heat exchangers. The inner wall pipe network having liquid outlet connected with a liquid intake of the outer wall pipe network. The propulsion assembly further includes means for circulating the liquid, connected to at least one liquid intake of the network of pipes of the inner wall.

Flow diverters for installation in mid-turbine frame systems at a conduit outlet of gas turbine engines are described. The flow diverters include a diverter body having a connector portion defining a diverter inlet, a diverter extension at least partially defining a diverter outlet, and a curved portion arranged between the connector portion and the diverter extension, the curved portion configured to change a direction of flow from a first direction to a second direction that is about 90° from the first direction as the flow passes from the diverter inlet to the diverter outlet.

Flow diverters for installation in mid-turbine frame systems at a conduit outlet of gas turbine engines are described. The flow diverters include a diverter body having a connector portion defining a diverter inlet, a diverter extension at least partially defining a diverter outlet, and a curved portion arranged between the connector portion and the diverter extension, the curved portion configured to change a direction of flow from a first direction to a second direction that is about 90° from the first direction as the flow passes from the diverter inlet to the diverter outlet.

A multi-engine system includes a first gas turbine engine that includes a first compressor and a first turbine. The multi-engine system may further include a second gas turbine engine that has a second compressor and a second turbine. Still further, the multi-engine system may include a first crossover cooling network configured to route a first crossover airflow from the first compressor of the first gas turbine engine to the second turbine of the second gas turbine engine and a second crossover cooling network configured to route a second crossover airflow from the second compressor of the second gas turbine engine to the first turbine of the first gas turbine engine.

A multi-engine system includes a first gas turbine engine that includes a first compressor and a first turbine. The multi-engine system may further include a second gas turbine engine that has a second compressor and a second turbine. Still further, the multi-engine system may include a first crossover cooling network configured to route a first crossover airflow from the first compressor of the first gas turbine engine to the second turbine of the second gas turbine engine and a second crossover cooling network configured to route a second crossover airflow from the second compressor of the second gas turbine engine to the first turbine of the first gas turbine engine.

A gas turbine engine has a compressor section, a combustor, and a turbine section. An associated fluid is to be cooled and an associated fluid is to be heated. A transcritical vapor cycle heats the fluid to be heated, and cools the fluid to be cooled. The transcritical vapor cycle includes a gas cooler in which the fluid to be heated is heated by a refrigerant in the transcritical vapor cycle. An evaporator heat exchanger at which the fluid to be cooled is cooled by the refrigerant in the transcritical vapor cycle. A compressor upstream of the gas cooler compresses the refrigerant to a pressure above a critical point for the refrigerant. An expansion device expands the refrigerant downstream of the gas cooler, with the evaporator heat exchanger being downstream of the expansion device, and such that the refrigerant passing through the gas cooler to heat the fluid to be heated is generally above the critical point.