Injection System for an Aircraft Jet Engine with Coolant Injection into the Combustor

The paper deals with an aircraft single jet turbo engine with coolant injection into its combustion chamber. The coolant injection system (CIS) is studied as a controller; it was modeled starting from its non-linear equations, then brought to a linear dimensionless form. Its transfer function was determined and a study about its stability was also performed. The embedded system (engine+CIS) quality was evaluated by studying its time behavior (some Simulink-Matlab simulations were performed), comparing the basic engine to the engine with CIS (with pneumatically or electrically driven coolant injection pump). Quantitative determinations are based on previous research results developed in Aerospace Engineering Laboratories in University of Craiova and on existing aircraft engines models (taken from technical scientific literature and author's previous contributions).