The ventilation process of the aviation piston two-stroke engine directly affects the engine performance

and the variable exhaust valve can improve the dynamic performance of engine. Through the GT-Power to build the one-dimensional engine model

simulation research about ventilation process of the engine at different speeds and different exhaust valve stages was carried out

and the influence of exhaust valve stage on the ventilation process was analyzed. On this basis

the stage of the exhaust valve under constant speed cruise conditions (speed of 6500r/min

50% throttle opening) was also optimized. The results show that different exhaust valve stage can change the phase of pressure fluctuations during engine exhaust process

thereby affecting the engines ventilation quality and combustion process; under constant speed cruise conditions

when the exhaust valve is at medium stage (primary valve is closed

secondary valve is open)

engine power performance is the best.