Embedded Control System for an Aircraft High Bypass Turbofan with Coolant Injection into the Compressor

Abstract

The author has studied a control system for an aircraft high-bypass turbofan. Engine’s basic control systems (for the fuel flow rate and for the exhaust nozzle opening) are completed by the coolant injection flow rate controller. Most important turbofan’s performance is the total thrust, so as main outputs were considered engine’s spools’ rotational speeds (which are measurable parameters and are proportional to engine’s thrust), to describe the turbofan as controlled object; meanwhile, the combustor’s temperature, as secondary output was also considered. One has chosen the architectures of all involved controllers and has created a convenient embedded control architecture, given that the turbofan has a single input – its power lever position. Starting from controllers’ mathematical models, one has built the embedded control system block diagram with transfer functions; it was the base for the performed Simulink-Matlab simulations. Simulation conclusions about embedded system quality (the behavior of system’s main output parameters) are revealed, as well as some observation concerning engine’s optimal control architecture.