Parametric analysis of transient performance of a turbojet engine based on nonlinear aero-thermodynamic modeling approach

The present study deals with the parametric analysis of a turbojet engine performance based on transient aero-thermodynamic governing equations. The required dynamic model developed in Simulink environment. From the complex factors affecting on transient performance, three factors including rotor dynamic, volume dynamic and heat soakage is presented in the model. To validate the model results, a deceleration operation from 100% to 70% of the design rotor speed is carried out and rotational speed, thrust, turbine inlet temperature and turbine exhaust gas temperature of the present model results were compared with commercial program GSP. The results show the ability of the model to simulate the transient performance so that the maximum percentage error is less than 4 percent in thrust prediction. Then in the transient response of the engine acceleration from 70% to 100% of the rotor speed, three different rate of fuel consumption is studied. The results indicate that with sudden acceleration, temperature overshoot at the inlet to the turbine and the occurrence of compressor surge can be harmful, such that the engine acceleration during 2.5 (s) can increase turbine inlet temperature to about 21 K with respect to reference value.