Numerical study on long-duration performance of solid-fuel scramjet with size-fixed aft channel

In this study, the changing performance characteristics of a solid-fuel scramjet with a size-fixed aft channel for a long-duration operation were investigated using numerical methods. The results show that a solid-fuel scramjet with such a chamber configuration can continuously provide effective thrust over a long working period, followed by a long tail section of thrust. The effective working period lasts from the beginning of the operation to the moment when the bottom wall covered by the solid fuel is exposed to hot gas. The fluctuation in the thrust is significant due to the relatively large fluctuation in the equivalence ratio. The solid fuel utilization is relatively low; approximately 49% of the solid fuel remains after the effective working period. The configuration used in this study limits the mass flow rate passing through the front part of the cavity significantly, thereby forcing the core of the main recirculation zone to move downward rapidly, with undesirable effects on the equivalence ratio fluctuation and utilization of the front part of the solid fuel.