Numerical investigation on geometric sensitivity and flame stabilisation mechanism in H2 fueled two-strut based scramjet combustor

Abstract

The layout of the strut fuel injector has a significant impact on the flame stabilization process of the strut-based scramjet combustor. That’s why a two-strut-based scramjet model has been developed in recent researches. As several recent studies have shown that the two-strut model performs better than a single-strut model in terms of performance parameters, the current research thus focuses on the effect of geometric sensitivity to the combustion flow-field as well as flame stabilization mechanism of the two-strut scramjet engine. To begin with, the adopted computational approaches are validated using experimental data from the existing literature for a single strut. Following that, multiple ramp positions are imported onto the existing two-strut geometry and then divergence angles on both the walls of the two-strut combustor are also varied to explore the combustion performance. The present investigation reveals that geometric variation has a significant influence on the performance study of a supersonic combustor. Increasing the ramp position from the combustor entrance leads to a slight improvement in combustion efficiency but at the cost of a corresponding increase in total pressure loss. Moreover, increasing the divergence angle on both walls weakens the combustion performance to some extent. Finally, a flame stabilization analysis is carried out in a two-strut model, which identifies two stable modes of combustion in the same way as single strut geometry does, suggesting that two-strut geometry can be adopted as an effective flame holder in future works.