Method for cooling a thermal protection floor of an aft aerodynamic fairing of a structure for mounting an aircraft propulsion system

A propulsion system for an aircraft, including a dual-flow turbojet and a mounting structure intended to mount said turbojet to the wing surface or to the fuselage of the aircraft, said mounting structure including an aft aerodynamic fairing including a thermal protection floor to protect said mounting structure from heat of a primary airstream channeled by an exhaust nozzle of said turbojet, said propulsion system comprising:

• extraction means for extracting a cooling airstream from a secondary airstream of said turbojet, together with an air circulator fed by said extraction means, said air circulator having at least one outlet aperture emerging into a space defined by a gap between said thermal protection floor and said exhaust nozzle, the outlet aperture is located upstream from a trailing edge of the exhaust nozzle,
• wherein said extraction means include at least one air inlet connected to said air circulator and formed in an aerodynamic wall of said propulsion system, said aerodynamic wall being followed by said secondary airstream during operation, said aerodynamic wall extending longitudinally opposite another similar aerodynamic wall of said propulsion system, said aerodynamic wall delimiting with said another similar aerodynamic wall a cavity separated from said secondary airstream,
• wherein said aerodynamic fairing extends in an extension of a bifurcation formed of two bifurcation walls mutually connecting two annular nacelle cases respectively internally and externally delimiting an annular space for the secondary airstream to flow in said turbojet, and said aerodynamic walls being said bifurcation walls or side walls of said aft aerodynamic fairing.