Conceptual study of a scramjet with symmetrical internal compression system

Abstract This paper focuses on the design analysis of a planar hydrogen-powered scramjet constructed with a symmetrical internal compression system of rectangular cross-sectional area, developed to demonstrate supersonic combustion in atmospheric flight at 30 km of altitude and velocity of 2050 m/s, equivalent to Mach number 6.8. In this analysis, is proposed an analytical approach based on theories of oblique shock wave optimized by the criterion of maximum total pressure recovery, Rayleigh flow’s and the area ratio coupled to Prandtl–Meyer to dimension the compression, combustion, and expansion sections. The design of the compression system was developed to provide velocity, and temperature sufficiently adequate for spontaneous supersonic combustion of the hydrogen-air mixture. The atmospheric airflow was modeled by the hypothesis of calorically perfect gas without viscous effects. A visualization of the effects of various flow phenomena, such as shock waves, combustion, and expansion waves, on the evolution of thermodynamic properties throughout the scramjet demonstrator is discussed. The results showed by conducted compression performance analysis, a major increase in entropy in the reflected shock wave where the criterion of shock waves of equal strength was not applied. Also, the airflow thermodynamic properties and velocity from the leading edge to the trailing edge were analyzed. With heat addition, the scramjet was able to produce uninstalled thrust.