Active Control of a Scramjet Engine

Scramjet engines are designed to operate across a wide Mach number range and typically incorporate isolator sections to provide sufficient back-pressure margin and prevent unstart. As military requirements become increasingly demanding, an active, closed-loop control system is necessary to maintain engine stability and power output. During Phase I, key components of a scramjet control system were developed, integrated, and tested on a proof-of-concept platform. In Phase II, the cavity shock trap geometry will be further optimized using a computational approach and the results experimentally validated. In addition, its ability to withstand a transient increase in backpressure will be explored. The multi-faceted skin friction sensors developed in Phase I will be optimized and combined into a single, commercial-grade unit. High-enthalpy pressure transducers will also be developed and tested. Reduced Order Models (ROMs) will be constructed and incorporated into the control algorithm, enabling it to detect potential unstart conditions and preemptively avert unstart. To investigate potential opportunities in scramjet flame-holding capabilities and combustion efficiency control, the cavity mixing processes, particularly while under direct excitation of the shear layer instabilities, will be explored. Finally, the system capabilities will be demonstrated at the ARC and in a government scramjet test facility.