A Framework for Simulating Turbine-Based Combined- Cycle Inlet Mode-Transition

Abstract

A simulation framework based on the Memory-Mapped-Files technique was created to operate multiple numerical processes in locked time-steps and send I/O data synchronously across to one-another to simulate system-dynamics. This simulation scheme is currently used to study the complex interactions between inlet flow-dynamics, variable-geometry actuation mechanisms, and flow-controls in the transition from the supersonic to hypersonic conditions and vice-versa. A study of Mode-Transition Control for a high-speed inlet windtunnel model with this MMF-based framework is presented to illustrate this scheme and demonstrate its usefulness in simulating supersonic and hypersonic inlet dynamics and controls or other types of complex systems. Nomenclature

Highlights from a Mach 4 Experimental Demonstration of Inlet Mode Transition for Turbine-Based Combined Cycle Hypersonic Propulsion

“…These data were used validate design and analysis approaches 14,15 and are available to prepare control laws for close-looped mode transition.…”

Survey on the mode transition technique in combined cycle propulsion systems

“…This allows for a potential slight decrease in vehicle speed without losing operability of the dual-mode scramjet (DMSJ) combustor. A framework based on the Memory-Mapped-Files technique has been developed as well, and it has been utilized to study the turbojet/ramjet mode transition control [32]. The aerodynamic performance of an over/under twin throat TBCC exhaust system during the turbojet/ramjet mode transition has been studied numerically, and the obtained results show that a great and sudden reduction in the lift force of the exhaust system during the mode transition would inevitably result in the dreadful variation of the pitching moment and consequently the severe trim problem for the hypersonic vehicle [33].…”

Analysis and Suppression of Thrust Trap for Turbo-Ramjet Mode Transition with the Integrated Optimal Control Method

“…A simulation framework based on the Memory-Mapped-Files technique was created to study the complex interactions between inlet flow dynamics, "variable geometry" actuation mechanisms, and flow controls in the transition from supersonic to hypersonic conditions and vice versa in Ref. [11].…”