Aircraft Jet-Engine Exhaust Nozzle with Pneumatic-Hydraulic Control Unit

The paper deals with an exhaust nozzle control unit for aircraft engines, based on combined pneumatic/hydraulic operating principles. From controller's non-linear motion equations one has obtained its mathematical model; one has applied the finite differences method in order to bring them to linear adimensional forms, then one has applied the Laplace transformation. Based on this mathematical model, controller's block diagram with transfer functions was built and its quality (its step response) was evaluated. A possible using of the nozzle's controller inside complex control architecture of a jet-engine was also studied; one has performed simulations (using Simulink-Matlab) concerning engine's output parameters' time behavior (their step responses), which lead to some conclusions, about controller's pre-design, further using possibilities as well as possibilities to continue and expand the carried out studies.