The current design assumes a single unstart event per flight. Repeated cycling may lead to fatigue of the hatch mechanism. Furthermore, the plasma actuator's power draw (≈1 kW) may be prohibitive for small-scale scramjets.
A. J. Reed, M. Takahashi Laboratory for Advanced Propulsion Dynamics, Institute for Hypersonic Systems scramjet unblocker
[1] Curran, E. T. (2001). Scramjet engines: the first forty years. Journal of Propulsion and Power , 17(6), 1138-1148. [2] Matsuo, K., et al. (2009). Unstart phenomena in scramjet inlets. Progress in Aerospace Sciences , 45(8), 285-310. [3] Do, H., et al. (2011). Plasma-assisted flame stabilization in a scramjet. Combustion and Flame , 158(4), 755-763. [4] Reed, A. J. (2024). Fast-acting bleed systems for hypersonic inlet control. AIAA Journal , 62(1), 112-125. The current design assumes a single unstart event per flight
This paper proposes a — a dual-function subsystem that (a) provides a temporary high-speed bleed path for excess pressure and (b) uses a pulsed plasma actuator to re-establish a leading oblique shock structure. The unblocker acts as a “defibrillator” for the scramjet flowpath. Combustion and Flame