Parametric effects in a scramjet engine on the interaction between the air stream and the injection

Abstract

The mixing of fuel and air in supersonic flow plays a significant role in the enhancement of the performance of scramjet engines. In this article, the two-dimensional coupled implicit Reynolds-averaged Navier–Stokes equations and the standard k–ε turbulent model are introduced to investigate the interaction between the supersonic air flow and the helium stream injected into a typical scramjet engine. A range of different angles (30–150°) of both the incoming air stream and the helium injection under various pressure conditions (0.62–1.86 MPa) have been investigated to assess their impact on the mixing. It is shown among the cases studied for different helium injections that an angle of 90° produces the highest mixing efficiency. In the cases with a variable air stream angle, then the situation with a 30° air stream angle can achieve a higher mixing efficiency than other angles. In addition, with a higher pressure of the injection, the air stream and the helium mix better.