Numerical investigation on mixing improvement mechanism of transverse injection based scramjet combustor

Abstract

The major hurdle in augmenting the performance of supersonic engines is the appropriate distribution of injected fuel within the supersonic chamber. That's why SSTk−ω model is used to explore the mixing characteristics of a transverse jet injection into a supersonic airstream. In this aspect, initially, the performance of the supersonic combustor is analysed using hydrogen and ethylene fuel in terms of mixing efficiency. Our results suggest that the flame holding capacity of hydrogen-fuelled combustor is better as than an ethylene-fuelled combustor. Additionally, to strengthen the mixing of fuel with supersonic air-flow, a novel shock generator is introduced and placed at different locations of the combustor. The flow-structure is studied comprehensively using two single shock generator and two dual shock generator to conclude the best possible geometry for improved performance. The results reveal that the fuel penetration depth of geometry 3 with dual shock generator has increased considerably. Moreover, geometry 3 offers enhanced mixing between the supersonic air and fuel compared to remaining models with the formation of a strong vortex pair and recirculation zone near the injection slot.