The investigation of core engine and derivative aero-engine development was presented.The increase in engine thrust can be realized by increasing air flow or cycle power of the core engine.But the margin of rotor speed

flow capacity and power needed of the turbomachinery should be considered early in the design stage.Serial development based on the core engine can be done by keeping the corrected speed of the high-pressure compressor constant

or keeping the maximum gas temperature constant.In practice

both of the foregoing approaches were adopted.Therefore

the margin of the maximum gas temperature

rotor speed and capability of HP compressor are required during the development of core engine and baseline aero-engine.However

the approaches in developing high bypass ratio engine and low bypass ratio engine are different.