| Abstract:To investigate the performance gain of the single bypass variable cycle engine, we established a simulation model and veri?
fied its computational accuracy through examples. The simulation and generation of the best variable geometry parameters, throttling
characteristics, and altitude-velocity characteristics for the three variable geometry schemes are based on the engine control laws and
optimal control objectives for different flight states. The study indicates that Scheme 3, which employs a variable geometry scheme with
adjustable tail nozzle, mixer, and low-pressure turbine guide, outperforms Scheme 1, the conventional engine variable geometry scheme.
Scheme 3 reduces fuel consumption rate by 1.7% to 3.0% in ground throttling state, increases supersonic cruise thrust by 14% to 29%, and
reduces fuel consumption rate by 0.9% to 3.1% in subsonic cruise. This represents the largest performance gain among the three variable
geometry schemes. Scheme 2, the variable geometry scheme with an adjustable tail nozzle and mixer, can reduce fuel consumption rate by
1.2% to 2.2% in ground throttling state, increase supersonic cruise thrust by 3% to 17%, and reduce subsonic cruise fuel consumption rate
by 0.9% to 1.2%. Among the three variable geometry schemes, Scheme 2 exhibits intermediate performance gains.When selecting engine
geometry options, it is important to consider the balance between the costs of structural complexity, reliability, and mass, and the overall
performance gains based on specific mission requirements. |
