Passively-driven bleed source switching

A gas turbine engine, comprising:

• a compressor section;
• a turbine section operably connected to the compressor section;
• and
• a bleed air cooling system, comprising:
• one or more bleed flowpaths operably connected to a bleed outlet to divert a bleed airflow from a gas turbine engine flowpath, each bleed flowpath including:
• two or more bleed ports disposed at separate axial locations of the gas turbine engine to divert a bleed airflow from a gas turbine engine flowpath;
• a bleed duct in fluid communication with the bleed ports and configured to convey the bleed airflow from the two or more bleed ports to the bleed outlet;
• and
• a delta-pressure valve disposed at each bleed port of the two or more bleed ports, the delta-pressure valve configured to move between an opened position and a closed position in response to a difference between a first pressure at a first location upstream of the delta-pressure valve and a second pressure at a second location downstream of the delta-pressure valve;
• wherein the bleed airflow is selectably conveyed through one of the two or more bleed ports depending on the operation of the associated delta-pressure valve;
• and
• wherein a first delta-pressure valve at a first bleed port of the two or more bleed ports is mechanically connected to a second delta-pressure valve at a second bleed port of the two or more bleed ports, such that opening of the first delta-pressure valve forces closure of the second delta-pressure valve via the mechanical connection.

A method of cooling one or more components of a gas turbine engine, comprising:

• selectably urging a bleed airflow through a first bleed port of a plurality of bleed ports each disposed at an axial location of a compressor section of a gas turbine engine, the bleed airflow selectably urged through the first bleed port via selective operation of a plurality of delta-pressure valves located at the plurality of bleed ports;
• and
• flowing the bleed airflow through a bleed duct toward a bleed outlet disposed at a cooling location;
• and
• wherein opening of a first delta-pressure valve of the plurality of delta-pressure valves forces closure of a second delta-pressure valve of the plurality of delta-pressure valves via a mechanical connection of the first delta-pressure valve to the second delta-pressure valve.