Study on scramjet engines with complex inlet flow conditions

Abstract

Scramjet engine is one of the key technologies to realize hypersonic flight. It has great research value for its performance under complex inlet flow conditions. In this paper, the free jet test model of RBCC aircraft is established, and the numerical simulation is carried out with Japanese NAL direct connected hydrogen fuel combustion chamber test. Aiming at the problems of coupling analysis accuracy and long calculation period, a one-dimensional internal flow coupling analysis method based on one-dimensional flow is proposed to solve the backpressure problem in the subsonic combustion state. The experimental results show that this method can predict the flow separation point in the isolation section well in the subsonic combustion mode, and the error is less than 10%, the prediction results of the peak pressure and the mean pressure along the passage are less than 23% and 10.4%, respectively. In the supersonic combustion mode, the accuracy of one-dimensional flow is higher, and the prediction error for the peak pressure in the combustion chamber is less than 3.79%, and the prediction error for the location of the peak pressure is less than 2.3%.