Experimental Study on Combustion Mode Transition in a Scramjet with Parallel Injection

Abstract

Mode transition from weak combustion to strong combustion or vice versa in a scramjet engine is a critical phenomenon in designing such engines, because the thrust of each mode varies considerably. The mode transition is supposed to interact strongly with a so-called pseudo-shock wave or shock train. In order to control vehicles with scramjet engines, it is, therefore, essential to understand mode transition. Several studies concerning this phenomenon have been conducted and most of them used the wall fuel injection method, where the disturbance of the boundary layer due to the wall injection could not be avoided. In order to prevent this disturbance, a parallel injection method was used in this study. The experiments were conducted using the supersonic combustion facilities of