Numerical Analysis of Solid Fuel Scramjet Operating at Mach 4 to 6

Numerical simulations were performed to analyze the performance of solid fuel scramjet (SFSCRJ) operating at Mach 4 to 6, with the primary goal being to investigate the feasibility of low takeover speed for SFSCRJ. The numerical model was created based on previous experiments with a constant area isolator added before combustor. Airflow is changed to subsonic in isolator and return to supersonic in the diverging section at the Mach 4 condition. The flow was not thermally choked at higher Mach condition, with a series of compression and expansion waves generating in the flameholding zone. The effect of flight Mach number is discussed from a viewpoint of total pressure recovery and combustion efficiency. The results show the feasibility of SFSCRJ operating at low flight Mach. To investigate the effect of inflow condition on combustor performance, different contraction ratios in the inlet are assumed at flight Mach 5 condition, resulting in different pressures at the entrance of isolator for numerical simulations. It is found that the performance of combustor is enhanced with the increase of inflow static pressure. There exists a tradeoff between the improved performance of combustor and the increased total pressure loss in the inlet.