Control of Unstart Phenomenon in a Hydrogen Fuelled Scramjet model

The present work involves the development of a numerical methodology to model supersonic combustion using 8 species, 13-reaction chemical model. The governing equations of continuity, momentum, energy, and combustion(species conservation) have been solved using commercial code of Fluent. The methodology has been then used to model the unstart phenomenon in a scramjet engine. A control system based on the mitigation of unstart by leaking high-pressure fluid from the slots designed on the lower and sidewall of the scramjet has been studied[1]. The effect of the slot size position on control mechanism has been studied. The unstart is initiated by a) raising a solid flap downstream of the isolator b) heat release due to combustion of fuel. An automatic slot control mechanism has been suggested to control the unstart phenomenon. The effect of bleeding ratio through slots on engine performance parameters has also been explored.

References: [1] Varshney, M., & Baig, M. F. (2019). Unstart Control in Scramjet Engines. In AIAA Scitech 2019 Forum (p. 0297).