Analysis and Possible Improvements of Scramjet Engines: The Effective Thrust and the Combustion Stability Problems

Abstract

The scramjet is the representative of the future jet engine, and it has irreplaceable advantages in terms of working performance and service life. Although it has been developed more than fifty years, there are many problems in the driven system of the scramjet engine. This paper mainly focuses on the problems of the effective thrust and the combustion stability. The research shows that how the pressure ratio affects the positive thrust and the combustion stability. Furthermore, this paper also shows that the elements which can affect the pressure ratio. The lower inlet air temperature is beneficial to enhance the thrust. According to the relevant research which apply the CJ detonation theorem to find the possible reason for the combustion instability. For the possible improvements, the research found that the engine thrust at different speed and the allowable maximum speed. The type of fuel and the reactivity of the fuel can influence the thrust.