Turbojet Engine Modeling Based on Multi-Variables Optimized Method

Modeling of control system is one the most prominent and sensitive parts of gas turbine engine design. In this paper an algorithm based on Optimized Iterative method and thermodynamic analysis is proposed. It uses engine components characteristic maps (including compressor and turbine) and presents a control model for gas turbine engine. An important duty of control system is regulating the output power or thrust of aircraft engines according to the most safe and optimum performance conditions. Utilizing this model a more precise prediction of engine behavior in transient and steady states could be obtained As a result the engine could be guided in the user determined running line before Engine critical conditions (such as compressor surge and violating the maximum tolerable temperature). In order to validate our model, its output is compared to experimental results of Olympus microjet engine test. Moreover, the error of this model is compared to error of typical PI model. The proposed model has desired precision and simple implementation. It might be used for either active or passive control systems. The models comparison illustrated that the error of proposed model for Olympus microjet engine is 6% maximum error for all parameters in any condition. It is very less than proportional-integral control system model for Steady-state and transient conditions. Finally Real-Time model generate based on proposed model & validate with test case. The presented model is very flexible and it might be developed for various types of more complex gas engines.

Keywords:

Off-Design , Steady state Running Line , Transient , Gas Turbine Controlling.