According to the wide-speed-range variable-cycle engine for driving the low-pressure
turbine rotor based on the interstage
combustion chamber, firstly, the interstage
combustion chamber is opened, a
turbofan interstage afterburning cycle mode is started, the thrust of the engine is greatly increased, meanwhile, all the first
mode selection valves are opened, and the second
mode selection valve is closed; therefore, more air flow with
high oxygen content enters the internal duct
afterburner, an internal duct
afterburner mode is started, and Ma0-2.5 + flight is realized. When Ma reaches 2.5-6, a
turbine engine core engine is closed, meanwhile, first
modal selection valves are all opened, a duct second
modal selection valve at an inlet of an interstage
combustion chamber is gradually opened, a part of air pressurized by a fan enters the interstage
combustion chamber I through the second
modal selection valve, a low-pressure
turbine is driven to drive a fan A to rotate and pressurize, and the fan A is driven to rotate and pressurize; after air flow pressurized by the engine fan A enters the outer duct, the dual-mode
ramjet engine is started and enters a
stamping mode, and Ma2.5-6 flight is achieved.