In order to simulate the transition state performance of air-turbo-ramjet(ATR)engine

an ATR engine model was established.The ATR engine fuel feeding law and the acceleration/deceleration performance were obtained through comparing to the traditional turbojet fuel feeding principle.The result shows that the ATR engine is more flexible in the selection of fuel feeding law and would satisfy the requirement of surge margin better.The engine start process could be simulated by this model after adding low speed of rotation characteristic according to the charateristic of ATR engine.