Refreshing heat management fluid in a turbomachine

A method of cooling fluid streams, the method comprising:

• directing a first fluid stream from a first duct across or through a first heat exchanger;
• directing the first fluid stream across or through a second heat exchanger after discharging from the first heat exchanger;
• and
• directing a second fluid stream from a second duct to the first duct, the second duct fluidly communicating with the first duct between the first heat exchanger and the second heat exchanger.

A turbomachine, comprising:

• a core engine;
• an annular first casing surrounding the core engine;
• an annular second casing spaced radially outward from the first casing and concentric therewith;
• an annular third casing spaced radially between the first casing and the second casing and concentric therewith;
• a first duct defined radially between the annular first casing and the annular third casing;
• a second duct defined radially between the annular second casing and the annular third casing;
• a plurality of first heat exchangers disposed radially about the first duct, the plurality of first heat exchangers respectively configured and arranged to receive a respective portion of a first fluid stream from the first duct;
• and
• a plurality of second heat exchangers disposed radially about the first duct downstream from the plurality of first heat exchangers, the plurality of second heat exchangers respectively configured and arranged to receive a respective portion of the first fluid stream after discharging from respective ones of the plurality of first heat exchangers;
• wherein the second duct fluidly communicates with the first duct between respective ones of the plurality of first heat exchangers and the plurality of second heat exchangers at a plurality of circumferentially disposed locations about the annular third casing, the plurality of circumferentially disposed locations respectively configured and arranged to introduce a respective portion of a second fluid stream from the second duct to the first duct.